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Electronic and thermoelectric properties of YbMg_(2)X_(2)(X=P,As,Sb,Bi)zintl compounds by first-principles method

Journal of Rare Earths 2024年第1期42卷 147-154,I0006页

作者： Sajid khan Dil Faraz khan R.Neffati Tariq Usman Muhammad Waqar Ahsraf shamim khan Saeed Ullah Jan G.Murtaza Department of Physics University of Science&Technology BannuBannu28100Pakistan Department of Physics Faculty of ScienceKing Khalid UniversityP.O.Box 9004AbhaSaudi Arabia Laboratoire de Physique de La Matiere Condensee Departement de PhysiqueFaculte des Sciences de TunisUniversite Tunis El ManarCampus Universitaire1060TunisTunisia Department of Physics Shaoxing UniversityShaoxing312000China Department of Mathematics&Natural Sciences Prince Mohammad Bin Fahd UniversityAlkhobar31952Saudi Arabia Materials Modeling Lab Department of PhysicsIslamia College Peshawar25120KhyberPakhtunkhwaPakistan

In this work the structural,electronic and thermoelectric properties of YbMg_(2)X_(2)(X=P,As,Sb,Bi)zintl compounds were investigated comprehensively using first principles *** electronic properties were studied using PBE GGA,TB-mBJ and hybrid(YS-PBE0)*** the structural parameters of optimized structures are in harmonious agreement to the available *** band structure study illustrates that the titled materials manifest metallic and semi metallic nature using PBE and TB-mBJ potentials while they show wide band gap semiconducting behavior by following hybrid(YS-PBE0)*** density of states(TDOS)and partial density of states(PDOS)were also calculated to glimpse the contribution of orbitals of atoms in the formation of *** properties were studied by using BoltzTraP2 code employed to *** get enormous values of Seebeck coefficient(S),power factor(PF)and thermoelectric figure of merit(ZT)for all the samples YbMg_(2)X_(2)(X=P,As,Sb,Bi),Moreover,the overwhelming transport properties for the titled compounds indicate the optimum level of carriers’concentration which pinpoints these materials to be better thermoelectrics in the 1-2-2 zintl family.

关键词： Zintl compounds Hybrid functional Band structure Thermoelectrics Rare earths

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Microplastics and heavy metals in freshwater fish species in the southwestern region of Bangladesh:An emerging concern for public health

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Emerging Contaminants 2024年第3期10卷 145-157页

作者： Mst shamima Akter Tapos Kumar Chakraborty Gopal Chandra Ghosh Md Simoon Nice Samina Zaman Abu shamim khan Department of Environmental Science and Technology Jashore University of Science and TechnologyJashore 7408Bangladesh Environmental Laboratory Asia Arsenic NetworkJashore 7400Bangladesh

Microplastics(MPs)pollution and its associated toxicity raising concerns among scientists as a result of their toxicological impacts on human health and the *** study aims to investigate the microplastics and heavy metals(HMs)contamination in seventeen freshwater fish species collected from the Southwestern region of *** extracted from these species using the hydrogen peroxide digestion method and characterized by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy(ATR-FTIR).Atomic Absorption Spectrometry(AAS)was used to determine the concentration of HMs in different species for evaluating human health risks.A total of 142 microplastic particles were extracted with an average concentration of 1.13±0.84 items per individual of fish,where the highest microplastics were found in ***(3.43±3.15 items)and lowest in ***(0.14±0.38 items).Identified microplastics were dominated byCu(0.01e1.14;0.50±0.44)>Pb(0.04e0.58;0.22±0.12)>Cd(0.00e0.11;0.03±0.03),*** metals-based human health risk assessment results show that there are no major non-carcinogenic health risks(THI<1),while higher carcinogenic risks are present for consumers.

关键词： Microplastics Edible fish Polymer type Heavy metals Human health risk Bangladesh

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Petrogenetic study of Mesoproterozoic volcanic rocks of North Delhi fold belt, NW Indian shield: implications for mantle conditions during Proterozoic

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Chinese Journal Of Geochemistry 2015年第1期34卷 93-114页

作者： M.S.Azam M.shamim khan M.Raza IGNOU Regional Center Department of Geology AMU

Mesoproterozoic North Delhi fold belt of NW Indian shield comprises three volcano-sedimentary basins viz. Bayana, Alwar and Khetri aligned parallel to each other from east to west. Each basin contains excellent exposures of mafic volcanic rocks. Major, trace and rare earth element abundances of volcanic rocks of the three basins are significantly diverse. Bayana and Alwar volcanics are tholeiites bearing close similarity with low Ticontinental flood basalts. However, Bayana volcanics are characteristically enriched in incompatible trace elements and REEs while Alwar volcanics display least enriched incompatible trace element abundances and flat REE patterns. The Khetri volcanics exhibit a transitional composition between tholeiite and calc-alkaline basalts. REE based source modeling suggests that Bayana suite was formed from the melts derived from 1 % to 10 %(avg.4 %) of the partial melting of a spinel lherzolite source giving a residual mineralogy of 56 % Olv, 25 % Opx and19 % Cpx. Whereas Alwar suite evolved through 12 %–20 %(avg. 15 %) partial melting of the same source with a residual mineralogy 61 % Olv, 25 % Opx and 14 % *** volcanics are exposed at two localities Kolihan and Madhan–Kudhan. The Kolihan volcanics were derived from 1 % to 6 %(avg. 4 %) partial melting with residualmineralogy 56 % Olv, 25 % Opx and 19 % Cpx whereas the magma of Madhan Kudhan volcanic suite was generated by 15%–30 % partial melting of the same source leaving behind 64 % Olv, 25 % Opx and 11 % Cpx as residual mineralogy. This source modeling proves that melts of Bayana and Alwar tholeiites were generated by partial melting of a common source within the spinel stability field under the influence of mantle plume. During the course of ascent, Bayana melts were crustally contaminated but Alwar melts remained unaffected. There was two tier magma production in Khetri region, one from the partial melting of the mantle wedge overlying the subducted oceanic plate which formed Kolihan

关键词：基性火山岩中元古代西印度地幔柱褶皱带岩石成因西北地盾

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Physico-chemical properties and macrofauna of soils under various farming systems of cold arid region in Balochistan,Pakistan

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Journal of Mountain Science 2024年第8期21卷 2618-2630页

作者： khan Mehmood GUL shamim KAKAR Hidayatullah PANEZAI Sanaullah khan Nayab ZIAD Tariq NASEEM Mahrukh SHAHEEN Umbreen Department of Botany University of BalochistanQuetta 87300Pakistan Department of Natural Resource Sciences McGill University21111 Lakeshore Road Ste.Anne de BellevueQuébec H9X 3V9Canada Directorate of Agriculture Research Soil and Water TestingAgricultural Research InstituteQuetta 87300Pakistan Department of Geography and Regional Planning University of BalochistanQuetta 87300Pakistan Department of Zoology University of BalochistanQuetta 87300Pakistan

Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy *** is an agrarian region,mostly with orchards of various fruit *** study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this *** concentrations of soil organic matter(SOM),soil organic carbon(SOC),nutrients,pH,electrical conductivity,soil texture,and the abundance and number of species of soil macrofauna of the agricultural fields were *** agricultural fields were *** fields were orchards of apple,apricot or the mixture of apple and apricot trees and one field was a cropland,cultivated with wheat as a *** orchards were under conservation agricultural practices;whereas,the cropland was under conventional *** agricultural lands were 2-26 years *** concentration of soil organic matter(SOM)in the upper 0-10 cm depth of these field sites ranged from 11.6 g kg^(-1)to 32.8 g kg^(-1)*** compared to cropland,orchards had significantly higher concentration of SOM and SOC.A total of 18 soil macrofauna species were found and the most common and abundant were ants(Monomorium minimum,Camponotus pennsylvanicus,Solenopsis invicta,and Lasius niger)followed by Arion ssp.(Brown Slug)and earthworm Lumbricus *** analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen,bioavailable phosphorus and *** existence of ants had no relationship with the concentration of SOM;whereas,existence of Lumbricus terrestris tended to had a positive relationship with the concentration of *** field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland,had two ant species *** indicates the positive influence of crop diversification on soil

关键词： Soil organic matter Macrofauna Land use history Tree-based intercropping Conservation agriculture

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Antidiarrheal potential of Distemonanthus benthamianus Baillon. extracts via inhibiting voltage-dependent calcium channels and cholinergic receptors

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Asian Pacific Journal of Tropical Biomedicine 2019年第11期9卷 449-455页

作者： William Yousseu Nana Gilbert Ateufack Marius Mbiantcha shamim khan Hafiz Majid Rasheed AlbertAtsamo Abdul Jabbar Shah Albert Kamanyi Taous khan Research Unit of Animal Physiology and Phytopharmacology Faculty of ScienceUniversity of DschangPO.Box 67 DschangCameroon Department of Pharmacy COMSATS University IslamabadAbbottabad Campus 22060Pakistan Laboratory of Animal Physiology Faculty of ScienceUniversity of Yaoundé1PO.Box 812 YaoundéCameroon

Objective:To evaluate spasmolytic mechanisms of aqueous and methanolic extracts from Distemonanthus benthamianus ***:Spasmolytic activities of extracts were evaluated in vitro on spontaneous and potassium chloride-induced jejunum contractions,or against cholinergic[acetylcholine(0.3μmol/L)]*** performance liquid chromatography analysis of both extracts was performed in reference to standard ***:Extracts developed concentration-dependent inhibitory *** methanolic extract,which revealed better activity,produced spasmolytic and myorelaxant effects at concentrations of 0.01-0.30 mg/mL with EC(50)of 0.06 and 0.09 mg/mL(95%CI:0.03-0.3 mg/mL),*** anticholinergic effect was obtained at the same concentrations with EC(50)of 0.11 mg/mL(95%CI:0.03-0.3 mg/mL).Chromatograms showed the presence of gallic acid in both extracts,rutin being only detected in the aqueous ***:Distemonanthus benthamianus extracts exhibit verapamil and atropine-like activities,thus highlighting calcium channels and muscarinic receptors blocking potentials,which may be conveyed by some phenolic *** results confirm the antidiarrheal activity of Distemonanthus benthamianus extracts.

关键词： Distemonanthus benthamianus HPLC Calcium-channels blocking Anticholinergic

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Orbital apex syndrome after tooth extraction in an immunocompromised patient

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International Journal of Ophthalmology(English edition) 2011年第1期4卷 112-114页

作者： Suresh Subramaniam Cheong Min Tet Wan Hazabbah Wan Hitam Adil Hussein shamim Ahmed khan Hillol Kanti Pal Zunaina Embong Department of Ophthalmology School of Medical SciencesUniversiti Sains MalaysiaHealth Campus Department of Ortorhinolaryngology School of Medical SciencesUniversiti Sains MalaysiaHealth Campus Department of Neurosciences School of Medical SciencesUniversiti Sains MalaysiaHealth Campus

A 60 year-old man presented with acute on set of left eye proptosis and ptosis. It was associated with poor vision, eye pain and restriction of eye movement of the same eye after 5 hours post left upper molar tooth extraction. The visual acuity in the left eye was hand movement. There was severe ptosis and proptosis of the left eye. The conjunctiva was chemotic with quite anterior chamber. The pupil was mid dilated and sluggished to light. The ocular movement was restricted in all directions. Fundoscopy of the left eye revealed features of central retinal artery occlusion with hyperaemic disc and subretinal exudates at posterior pole. The right eye appeared normal. Urgent MRI brain and orbit revealed severe left paranasal sinusitis with anterior displacement of the left globe and presence orbital abscess. Patient was managed with Otorhinolaryngology and Neurosurgery teams. He underwent emergency transnasal drainage of abscess. Histopathological examination of unhealthy sinus mucosa showed evidence of fungal infection. However, the culture and sensitivity result was inconclusive. Patient was treated with amphotericin B, ceftriaxone, amoxicillin clavulanate and metronidazole. Patient was detected to have high blood sugar level and was managed accordingly. The proptosis improved with treatment. However, his vision, ptosis and ophthalmoplegia remained static. Assessing the immunocompromised status is important for the management of patient presented as acute orbital apex syndrome to avoid fatal outcome.

关键词： orbital apex syndrome tooth extraction proptosis ptosis ophthalmoplegia

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Carbonatite Occurrence in Ambaji-Sendra Belt of NW Indian Shield: Evidence of Carbonatitic Magmatism in the Subduction Setting

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International Journal of Geosciences 2023年第1期14卷 52-74页

作者： Sadaf Siddiqui Sadaf Fatima Tavheed khan Mohammad shamim khan Department of Geology Aligarh Muslim University Aligarh India Oil and Natural Gas Corporation Nazira India Geochemistry Division CSIR-NGRI Hyderabad India

The paper represents a new discovery of a late Mesoproterozoic lenticular and discontinuous, carbonatitic body exposed at Basantgarh, Sendra and near the Abu-road area of the Ambaji-Sendra belt of the South Delhi Fold Belt. It is medium to coarse-grained and light to dark coloured compact rock. The common associates of the carbonatitic rock are felsic rocks, rich in alkalies. Carbonatite contains more than 50% carbonate minerals, the majority of which are calcite, dolomite, ankerite, augite-aegirine augite and plagioclase. It is classified as calcite carbonatite of the sövite variety due to its coarse-grained character, chemically as calico-carbonatite and magnesio-carbonatite and even as silico-carbonatites for having more than 20% SiO2. The ∑REE contents of calico-carbonatite samples are nearly 100 times greater than magnesio-carbonatite. Chondrite normalised REE profiles of calcio-carbonatites are LREE enriched with nearly flat HREEs whereas the magnesio-carbonatite is characterised by flat REE patterns. The mantle-normalized incompatible trace element spidergram of Ambaji-Sendra belt carbonatites shows distinct negative anomalies of Ba, Nb, Ta, P, Sm, Eu, Ti and Y and positive at U and Pb by calcio-carbonatite whereas the magnesio-carbonatite displays negative kinks at K, Zr, Nb, Ta and Ti and positive at Th, Pb and Sr. The variable and/or contrasting enrichment/depletion in various elements in the two types of Ambaji-Sendra belt carbonatite is attributed either to significant differences in the type and modal proportion of different accessory mineral species or selective incorporation of metasomatic fluids during the subduction process. The chemical attributes of Ambaji-Sendra belt carbonatite suggest its emplacement in subduction settings.

关键词： Aravalli Craton Ambaji-Sendra Belt Precambrian Carbonatite Subduction Set-ting

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Soft Sediment Deformation Structures in the Sediment Deposits of Ganga River and Its Oxbow Lakes in Parts of Indo-Gangetic Plain: Implications for Quake Proxies and Paleoseismicity Tracking

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International Journal of Geosciences 2023年第1期14卷 75-93页

作者： Gufran Ali Mohd Sajid Mohammad shamim khan Department of Geology AMU Aligarh India

The Late Quaternary thick sedimentary fills of the Ganga basin predominantly consist of unconsolidated fluvial sandy deposits which are often intercalated with mud. These deposits at various places record the evidence of earthquakes, which occurred in the recent geological past. The evidence is contained and manifested in the form of Soft Sediment Deformation Structures (SSDSs). Saturated sediments/muds/soils are liquefied by earthquake tremors which either generate SSDS or produce structural discordance in the pre-existing sedimentary structures. The present study reports the occurrence of SSDS, e.g. load and associated flame structures, clastic dikes and sill structures, slump structures and sedimentary breccias, etc. from the Ganga River and adjacent oxbow lake sediment deposits. An attempt has been made to establish the origin of soft sediment structures of this region in accordance with its neotectonic history and in turn, identification of seismic structural proxies to delineate paleoseismic events in this region with futuristic implications. The preservation of soft sediment deformation structures in large numbers with multiple geomorphology and scale, in the river and adjoining lake sediments, is indicative of frequent earthquakes of high magnitude consequent to tectonic activism in the Himalayan region.

关键词： Quaternary Sediments Flood Plain Central Ganga Basin Sediment Dynamism Himalayan Uplift Paleoquakes

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Geochemistry of Palaeoproterozoic Rocks of Aravalli Supergroup: Implications for Weathering History and Depositional Sequence

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International Journal of Geosciences 2017年第10期8卷 1278-1299页

作者： Pavanesh K. Singh M. shamim khan Department of Geology Aligarh Muslim University Aligarh India

The Paleoproterozoic Aravalli Supregroup of rocks, hosted in Aravalli Craton of NW shield, is deposited in shallow and deep water conditions. The major lithologies are phyllites and quartzites with significant components of greywacks and dolomite. Geochemical indices in particular, CIA (Chemical Index of Alteration) values (avg. phyllites: 51.6 - 81.5, avg. quartzites: 57.4 - 95.5) calculated from the data of clastic rocks of ASG suggest minimum to highly intense weathering in the source region. Other indices including PIA, CIW and ICV along with plot patterns on the A-CN-K diagram also nearly endorse CIA based interpretation. These rocks possess relatively high Th/U ratios compared to that found in fresh igneous rocks or their high grade metamorphic equivalents. This high Th/U ratio is neither a source inheritance nor a result of oxidation state rather a manifestation of Th hosting mineral accumulation through sorting. Viewed in the context of present stratigraphic succession, the weathering history adduced from geochemistry does not seem compatible but matches well with earlier classification scheme wherein the evolution of Aravalli Supergroup was considered episodic.

关键词： Clastic Geochemistry Aravalli Supergroup Rajasthan Palaeoweathering Indian Shield

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Hydro-geochemical evaluation of groundwater with studies on water quality index and suitability for drinking in Sagardari,Jashore

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Journal of Groundwater Science and Engineering 2020年第3期8卷 259-273页

作者： Mohammad Tofayal Ahmed Minhaj Uddin Monir Md Yeasir Hasan Md Mominur Rahman Md Shamiul Islam Rifat Md Naim Islam Abu shamim khan Md Mizanur Rahman Md Shajidul Islam Department of Petroleum and Mining Engineering Jashore University of Science and TechnologyJashore-7408Bangladesh Environmental Laboratory Asia Arsenic NetworkArsenic CenterBenapole RoadKrishnobatiPulerhatJashore-7400Bangladesh

Sagardari union is facing groundwater crisis because of contaminations from agriculture and urban sewage,which bring a considerable change in water *** view of this,hydro-chemical analyses were undertaken on 35 groundwater samples and the following hydro-geochemical parameters,pH,total dissolved solids(TDS),total hardness(TH),electrical conductivity(EC),cations and anions,were *** the analytical results,it is found that pH value was lower than WHO drinking water standard and the middledownstream portions of the investigation region show higher *** piper plot indicates that the groundwater in Sagardari falls in the categories of NaClHCO3 hydro-chemical *** TH in groundwater was detected,but still in an acceptable *** addition,salinity and arsenic ratio are higher and moderately higher,*** spatial distribution of Groundwater Quality Index(GWQI)was determined by geo-statistical modelling of Sagardari *** study provides information and supports the administration which to make better groundwater utilization and quality control in the Sagardari union.

关键词： Sagardari union Groundwater Hydro-geochemistry Spatial distribution Water quality index

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