Studying the impact of solar activity on the Earth's climate is significant for predicting the change of its elements for long periods. Most studies have focused on the relationship between sunspots and changes in one of the climate elements. In this research, the effect of the solar activities that consist of coronal mass ejections and solar flare, and the sunspots number on thunderstorms that occur during the winter season in Iraq for the period from (1996-2019) representing the Solar-Cycles 23 & 24, respectively, were investigated in this study. In general, the statistical results show that, the monthly average increase for each of the following: energies of coronal mass ejections, solar flares, and the sunspots number, the monthly frequency of thunderstorms decreases. The Solar-Cycle 24 is the weakest among the cycles of the last century; therefore, its results were not precise.
{"title":"STUDYING THE EFFECT OF SOLAR ACTIVITIES ON THUNDERSTORMS IN IRAQ FOR SOLAR-CYCLES 23 & 24","authors":"Mohammed Akeel Ramadan, Imad Hussain","doi":"10.22452/mjs.vol41no1.5","DOIUrl":"https://doi.org/10.22452/mjs.vol41no1.5","url":null,"abstract":"Studying the impact of solar activity on the Earth's climate is significant for predicting the change of its elements for long periods. Most studies have focused on the relationship between sunspots and changes in one of the climate elements. In this research, the effect of the solar activities that consist of coronal mass ejections and solar flare, and the sunspots number on thunderstorms that occur during the winter season in Iraq for the period from (1996-2019) representing the Solar-Cycles 23 & 24, respectively, were investigated in this study. In general, the statistical results show that, the monthly average increase for each of the following: energies of coronal mass ejections, solar flares, and the sunspots number, the monthly frequency of thunderstorms decreases. The Solar-Cycle 24 is the weakest among the cycles of the last century; therefore, its results were not precise.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46141845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Matin, Postdoc ,, Postdoc ,, M. Ibrahim, Tasnim Rahman Anisa, M. ., M. Rahman
Considering promising biological activities of natural and synthetic rhamnopyranoside esters, we have synthesized several methyl 4-O-pivaloyl-α-L-rhamnopyranosides via selective 2,3-O-acetonide protection of methyl α-L-rhamnopyranoside (4) followed by C-4 pivaloylation, and deprotection. The synthesized 4-O-pivaloate 7 and its 2,3-di-O-esters 8a-e are characterized by spectroscopy and are optimized by using density functional theory (DFT). The free energy and bond angles thus calculated are used to establish the probable conformation(s). The 2,3-O-acetonide protected rhamnopyranosides 5-6 are found to be slightly distorted from the regular 1C4 conformation, and exist between the chair and twist-boat (skew) conformation while other pivaloyl esters 7-8a-e exist in regular 1C4 chair conformation.
考虑到天然和人工合成的鼠李糖苷酯具有良好的生物活性，我们通过α- l-鼠李糖苷的选择性2,3- o -丙酮保护(4)，然后进行C-4酰化和去保护，合成了几种甲基4- o -戊酰-α- l-鼠李糖苷。对合成的4- o -戊酸酯7及其2,3-二o -酯8a-e进行了光谱表征，并用密度泛函理论(DFT)对其进行了优化。由此计算的自由能和键角被用来建立可能的构象。2,3- o -乙酰胺保护的鼠李核苷5-6被发现与规则的1C4构象有轻微的畸变，存在于椅子构象和扭船构象之间，而其他的七-8a-e则存在于规则的1C4椅子构象中。
{"title":"SYNTHESIS, CHARACTERIZATION, IN SILICO OPTIMIZATION, AND CONFORMATIONAL STUDIES OF METHYL 4-O-PIVALOYL-α-L-RHAMNOPYRANOSIDES","authors":"M. Matin, Postdoc ,, Postdoc ,, M. Ibrahim, Tasnim Rahman Anisa, M. ., M. Rahman","doi":"10.22452/mjs.vol41no1.6","DOIUrl":"https://doi.org/10.22452/mjs.vol41no1.6","url":null,"abstract":"Considering promising biological activities of natural and synthetic rhamnopyranoside esters, we have synthesized several methyl 4-O-pivaloyl-α-L-rhamnopyranosides via selective 2,3-O-acetonide protection of methyl α-L-rhamnopyranoside (4) followed by C-4 pivaloylation, and deprotection. The synthesized 4-O-pivaloate 7 and its 2,3-di-O-esters 8a-e are characterized by spectroscopy and are optimized by using density functional theory (DFT). The free energy and bond angles thus calculated are used to establish the probable conformation(s). The 2,3-O-acetonide protected rhamnopyranosides 5-6 are found to be slightly distorted from the regular 1C4 conformation, and exist between the chair and twist-boat (skew) conformation while other pivaloyl esters 7-8a-e exist in regular 1C4 chair conformation.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43692951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Hasan, Dian Samitra, M. Widodo, Izzul Islam, F. Ottoni
Rasborabaliensis(Hubbs & Brittan, 1954) is a native freshwater fish from Indonesia, which was described in East Java, Bali Island, and the West Lesser Sunda Islands. In the present paper, we reported on the presence of R. baliensis, which was collected from several new rivers in Java and East Lesser Sunda Islands. The specimen was identified as R. baliensisbased on the number of scales on the lateral line 26 and on the predorsal 12;the upper head and body are light brown while the lower jaw and belly are silver; mid-lateral stripe from opercle to caudal base light blue; dorsal, caudal, and anal fins yellowish; and pectoral and ventral fins hyaline. The paper also showed the current distribution range of this species. The new records of native freshwater fish are important contributions to understanding species diversity and biogeography.
{"title":"AN UPDATE CHECKLIST OF VULNERABLE FRESHWATER FISH RASBORA BALIENSIS (HUBBS & BRITTAN 1954) (CYPRINIFORMES: CYPRINIDAE) IN INDONESIA","authors":"V. Hasan, Dian Samitra, M. Widodo, Izzul Islam, F. Ottoni","doi":"10.22452/mjs.vol40no3.8","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.8","url":null,"abstract":"Rasborabaliensis(Hubbs & Brittan, 1954) is a native freshwater fish from Indonesia, which was described in East Java, Bali Island, and the West Lesser Sunda Islands. In the present paper, we reported on the presence of R. baliensis, which was collected from several new rivers in Java and East Lesser Sunda Islands. The specimen was identified as R. baliensisbased on the number of scales on the lateral line 26 and on the predorsal 12;the upper head and body are light brown while the lower jaw and belly are silver; mid-lateral stripe from opercle to caudal base light blue; dorsal, caudal, and anal fins yellowish; and pectoral and ventral fins hyaline. The paper also showed the current distribution range of this species. The new records of native freshwater fish are important contributions to understanding species diversity and biogeography.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48368440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antibiotics are one of the most exploited metabolites produced by soil actinomycetes. This study isolated fifteen actinomycetes (A1 – A15) from dumpsite soils within Ilorin metropolis & screened them for antibacterial activity. Isolates were identified with morphology & biochemical characteristics.Their activity against clinical bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae & Staphylococcus aureus) was determined. Their bioactive metabolites after fermentation was assayed for by agar well diffusion & compared with reference antibiotics. Molecular analysis of two most active isolates was done. The most active metabolite was subjected to GCMS. All isolates were identified as Streptomyces, 7 isolates exhibited activity against 3 test bacteria with highest (10.5mm±0.35) by Streptomyces griseoplanus while S. aureus demonstrated total resistance to all isolates. Secondary activity revealed 7 of the metabolites as effective against the bacteria with highest activity (28.5±1.04mm) by S. sparsogenes showing similar activity with Cefuroxime (28.01±0.01mm). The two most active isolates were Streptomyces griseoplanus strain NR725RL-ISP 5009 & Streptomyces sparsogenes strain NBRC 1308616S & RNA nucleotide similarity revealed close phylogenic relationship. GC-MS revealed10 compounds in S. sparsogenes strain NBRC 1308616S metabolite. Streptomyces from dumpsite soils within Ilorin produced bioactive compounds against clinical test bacteria and thus could be potential sources of antibiotics.
{"title":"ISOLATION, CHARACTERIZATION AND ANTIBACTERIAL SREENING OF ANTIBIOTICS PRODUCED FROM STREPTOMYCES ISOLATED FROM DUMPSITE SOILS IN ILORIN, NORTH CENTRAL NIGERIA","authors":"Risikat Nike Ahmed, Mercy Oluwaseyi Bamigboye, Kamoldeen Abiodun Ajijolakewu, Sheriffdeen Olakunle Idris, Nimat Toyosi Ajide Bamigboye","doi":"10.22452/mjs.vol40no3.1","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.1","url":null,"abstract":"Antibiotics are one of the most exploited metabolites produced by soil actinomycetes. This study isolated fifteen actinomycetes (A1 – A15) from dumpsite soils within Ilorin metropolis & screened them for antibacterial activity. Isolates were identified with morphology & biochemical characteristics.Their activity against clinical bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae & Staphylococcus aureus) was determined. Their bioactive metabolites after fermentation was assayed for by agar well diffusion & compared with reference antibiotics. Molecular analysis of two most active isolates was done. The most active metabolite was subjected to GCMS. All isolates were identified as Streptomyces, 7 isolates exhibited activity against 3 test bacteria with highest (10.5mm±0.35) by Streptomyces griseoplanus while S. aureus demonstrated total resistance to all isolates. Secondary activity revealed 7 of the metabolites as effective against the bacteria with highest activity (28.5±1.04mm) by S. sparsogenes showing similar activity with Cefuroxime (28.01±0.01mm). The two most active isolates were Streptomyces griseoplanus strain NR725RL-ISP 5009 & Streptomyces sparsogenes strain NBRC 1308616S & RNA nucleotide similarity revealed close phylogenic relationship. GC-MS revealed10 compounds in S. sparsogenes strain NBRC 1308616S metabolite. Streptomyces from dumpsite soils within Ilorin produced bioactive compounds against clinical test bacteria and thus could be potential sources of antibiotics.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48217622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The boiled tea leaves residual was modified with oleum of weight 1:1 to prepare an adsorbent that is capable to adsorb nicotine on its surface. The surface properties of the sample were studied by using the FT-IR spectroscopy after each treatment resulting obvious peaks that indicate the modification of the sample with oleum and the adsorption of nicotine on its surface. The concentration of nicotine in the prepared solutions was measured by the use of spectral analysis. The change of nicotine΄s adsorption was studied with the change of time. An increase in the adsorbed amount was noticed until the equilibrium was reached after 24hours. In addition, an increase of the adsorbed amount of nicotine with the increase of its initial concentration was observed at the room temperature. The experimental data corresponded with adsorption models of Langmuir, Freundlish and Temkin, besides, a mechanism of the adsorption of nicotine was suggested to occur with the participation of the two nitrogen atoms.
{"title":"MODIFIED TEA LEAVES RESIDUAL FOR NICOTINE ADSORPTION","authors":"Y. W. AlBizreh, Rasha Almostafa, Malak Aljoubbeh","doi":"10.22452/mjs.vol40no3.3","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.3","url":null,"abstract":"The boiled tea leaves residual was modified with oleum of weight 1:1 to prepare an adsorbent that is capable to adsorb nicotine on its surface. The surface properties of the sample were studied by using the FT-IR spectroscopy after each treatment resulting obvious peaks that indicate the modification of the sample with oleum and the adsorption of nicotine on its surface. The concentration of nicotine in the prepared solutions was measured by the use of spectral analysis. The change of nicotine΄s adsorption was studied with the change of time. An increase in the adsorbed amount was noticed until the equilibrium was reached after 24hours. In addition, an increase of the adsorbed amount of nicotine with the increase of its initial concentration was observed at the room temperature. The experimental data corresponded with adsorption models of Langmuir, Freundlish and Temkin, besides, a mechanism of the adsorption of nicotine was suggested to occur with the participation of the two nitrogen atoms.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46809893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we study the theory of fuzzy limit of fuzzy function depending on the Altai’s principle and using the representation theorem (resolution principle) to run the fuzzy arithmetic.The novelty underlying this theory is that we can provethe convergence of afuzzy function to its fuzzy limit through proving the convergence of its 𝛼-cuts’boundaries to their limits for the membership degree 0<𝛼𝑜<𝛼1≤𝛼≤1.
{"title":"FUZZY LIMITS OF FUZZY FUNCTIONS","authors":"Abdulhameed Qahtan Abbood Altai","doi":"10.22452/mjs.vol40no3.7","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.7","url":null,"abstract":"In this paper, we study the theory of fuzzy limit of fuzzy function depending on the Altai’s principle and using the representation theorem (resolution principle) to run the fuzzy arithmetic.The novelty underlying this theory is that we can provethe convergence of afuzzy function to its fuzzy limit through proving the convergence of its 𝛼-cuts’boundaries to their limits for the membership degree 0<𝛼𝑜<𝛼1≤𝛼≤1.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46771132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nurazureen Matnin, Dayang Salwani Awang Adeni, M. N. Ahmad, N. Suhaili
Sago frond is produced in abundance upon harvesting of the sago palms for starch extraction, hence need to be utilized and developed into beneficial products. In this study, the sap which contains sugars and starch is obtained by roller crushing the skinned frond for use as fermentation medium. Fronds from different growth stages (namely Angkat punggung and Upong muda) and different positions within the rosette (inner and outer circle) of the sago palm were studied. Based on the results, the outer circle frond of Upong muda palm gave the highest volume of sap at 290mL/kg which equivalent to 1600 mL/frond. On top of that, sago frond sap has an acidic pH, with glucose as major sugar component and contained various kinds of minerals like calcium, potassium and manganese. All fronds from different growth stages contain glucose between 28-68 g/L and xylose 21-29 g/L, respectively. After 21 days of storage, it can be concluded that the amount of reducing sugars and starch in all samples obtained from different growth stages remained almost unchanged from the original. Subsequently after this study, both fresh and stored sago frond sap can be used as a fermentation substrate without any modification.
{"title":"THE CHARACTERISTICS OF SAGO FROND SAP FROM TWO SELECTED GROWTH STAGES; ANGKAT PUNGGUNG AND UPONG MUDA PALMS","authors":"Nurazureen Matnin, Dayang Salwani Awang Adeni, M. N. Ahmad, N. Suhaili","doi":"10.22452/mjs.vol40no3.4","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.4","url":null,"abstract":"Sago frond is produced in abundance upon harvesting of the sago palms for starch extraction, hence need to be utilized and developed into beneficial products. In this study, the sap which contains sugars and starch is obtained by roller crushing the skinned frond for use as fermentation medium. Fronds from different growth stages (namely Angkat punggung and Upong muda) and different positions within the rosette (inner and outer circle) of the sago palm were studied. Based on the results, the outer circle frond of Upong muda palm gave the highest volume of sap at 290mL/kg which equivalent to 1600 mL/frond. On top of that, sago frond sap has an acidic pH, with glucose as major sugar component and contained various kinds of minerals like calcium, potassium and manganese. All fronds from different growth stages contain glucose between 28-68 g/L and xylose 21-29 g/L, respectively. After 21 days of storage, it can be concluded that the amount of reducing sugars and starch in all samples obtained from different growth stages remained almost unchanged from the original. Subsequently after this study, both fresh and stored sago frond sap can be used as a fermentation substrate without any modification.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42566072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The establishment and survival of the population of species in their breeding ground can be attributed to the species’ reproductive characteristic and capacity. The Monopterus albus species is an introduced fish in the Philippines. It is a protogynous hermaphrodite which has a natural ability for sex reversal. This study describes the histomorphology of the different stages of gonadal maturation and determines the concentration levels of the steroid hormones 17ß-estradiol (E2) and testosterone (T) in the blood plasma. These aim to a further understanding on the gonadal development and sex differentiation of the rice paddy eel as a hermaphroditic fish. Fish samples were collected randomly from farm ponds located in three provinces within the island of Luzon, Philippines. The sexual identity of the fish was categorized based on the presence or absence of ovarian and testicular tissues. Histological analysis of the gonad showed that immature, maturing-matured female gonad exhibited ovarian tissues of varying stages. The intersex gonad showed the existence of both ovarian and testicular tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentration levels of gonadal steroid hormones. Differences in the concentration levels of the two hormones were evident across all the stages of gonad maturation. The functional role of these hormones in vitellogenesis and spermatogenesis leads to the development of this sex-changing gonads. This reproductive characteristic contributes to our understanding of the reproductive success of hermaphroditic fish.
{"title":"ELUCIDATING THE GONADAL DEVELOPMENT AND SEX DIFFERENTIATION OF THE RICE PADDY EEL, Monopterus albus (Zuiew, 1993), BASED ON GONADAL HISTOMORPHOLOGY AND STEROID HORMONE LEVELS","authors":"Dulce Marie Pili Nisperos, Gliceria B. Ramos","doi":"10.22452/mjs.vol40no3.2","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.2","url":null,"abstract":"The establishment and survival of the population of species in their breeding ground can be attributed to the species’ reproductive characteristic and capacity. The Monopterus albus species is an introduced fish in the Philippines. It is a protogynous hermaphrodite which has a natural ability for sex reversal. This study describes the histomorphology of the different stages of gonadal maturation and determines the concentration levels of the steroid hormones 17ß-estradiol (E2) and testosterone (T) in the blood plasma. These aim to a further understanding on the gonadal development and sex differentiation of the rice paddy eel as a hermaphroditic fish. Fish samples were collected randomly from farm ponds located in three provinces within the island of Luzon, Philippines. The sexual identity of the fish was categorized based on the presence or absence of ovarian and testicular tissues. Histological analysis of the gonad showed that immature, maturing-matured female gonad exhibited ovarian tissues of varying stages. The intersex gonad showed the existence of both ovarian and testicular tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentration levels of gonadal steroid hormones. Differences in the concentration levels of the two hormones were evident across all the stages of gonad maturation. The functional role of these hormones in vitellogenesis and spermatogenesis leads to the development of this sex-changing gonads. This reproductive characteristic contributes to our understanding of the reproductive success of hermaphroditic fish.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48502759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, by combining the Solodov and Svaiter projection technique with the conjugate gradient method for unconstrained optimization proposed by Mohamed et al. (2020), we develop a derivative-free conjugate gradient method to solve nonlinear equations with convex constraints. The proposed method involves a spectral parameter which satisfies the sufficient descent condition. The global convergence is proved under the assumption that the underlying mapping is Lipschitz continuous and satisfies a weaker monotonicity condition. Numerical experiment shows that the proposed method is efficient.
{"title":"AN EFFICIENT HYBRID DERIVATIVE-FREE PROJECTION ALGORITHM FOR CONSTRAINT NONLINEAR EQUATIONS","authors":"K. Muangchoo","doi":"10.22452/mjs.vol40no3.6","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.6","url":null,"abstract":"In this paper, by combining the Solodov and Svaiter projection technique with the conjugate gradient method for unconstrained optimization proposed by Mohamed et al. (2020), we develop a derivative-free conjugate gradient method to solve nonlinear equations with convex constraints. The proposed method involves a spectral parameter which satisfies the sufficient descent condition. The global convergence is proved under the assumption that the underlying mapping is Lipschitz continuous and satisfies a weaker monotonicity condition. Numerical experiment shows that the proposed method is efficient.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45961689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current study covenants with stochastic investigation of an integrated hardware-software system considering hardware failure, software up-gradation upon failure, precautionary maintenance (PM) after a pre-determined process time, maximum repair time of hardware and different weather conditions. All time dependent indiscriminate variables are arbitrarily dispersed. Some important reliability measures like MTSF, availability and revenue of the system are obtained by using well established techniques semi-Markov process. Regenerative point technique has also been taken into consideration during model development. Sensitivity analysis of these measures is also performed. Finally, empirical analysis is done to demonstrate the results for a specific case. To climax the significance of the study, graphs of MTSF, availability, profit and sensitivity are also depicted.
{"title":"STOCHASTIC MODELING AND SENSITIVITY ANALYSIS OF AN INTEGRATED HARDWARE-SOFTWARE SYSTEM SUBJECT TO DIFFERENT WEATHER CONDITIONS","authors":"M. Saini, Ashish Kumar","doi":"10.22452/mjs.vol40no3.5","DOIUrl":"https://doi.org/10.22452/mjs.vol40no3.5","url":null,"abstract":"The current study covenants with stochastic investigation of an integrated hardware-software system considering hardware failure, software up-gradation upon failure, precautionary maintenance (PM) after a pre-determined process time, maximum repair time of hardware and different weather conditions. All time dependent indiscriminate variables are arbitrarily dispersed. Some important reliability measures like MTSF, availability and revenue of the system are obtained by using well established techniques semi-Markov process. Regenerative point technique has also been taken into consideration during model development. Sensitivity analysis of these measures is also performed. Finally, empirical analysis is done to demonstrate the results for a specific case. To climax the significance of the study, graphs of MTSF, availability, profit and sensitivity are also depicted.","PeriodicalId":18094,"journal":{"name":"Malaysian journal of science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42055359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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