检索结果-南通市图书馆

Sensitivity enhancement of OD-and OD-CNT-based humidity sensors by high gravity thin film deposition technique

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2015年第3期36卷 69-73页

作者： Kh.S.Karimov Noshin Fatima Khaulah Sulaiman m.mahroof tahir Zubair Ahmad A.mateen Ghulam Ishaq Khan Institute of Engineering Sciences and Technology Center for Innovative Development of Science and Technologies of Academy of Sciences Low Dimensional materials Research Centre (LDmRC) Department of Physics Faculty of Science University of Malaya Saint Cloud State University Department of Chemistry and Earth Sciences Faculty of materials Science and Engineering Institute of Space Technology

The humidity sensing properties of the thin films of an organic semiconductor material orange dye （OD） and its composite with CNTs deposited at high gravity conditions have been reported. Impedance, phase angle, ca- pacitance and dissipation of the samples were measured at 1 kHz and room temperature conditions. The impedance decreases and capacitance increases with an increase in the humidity level. It was found that the sensitivity of the OD-based thin film samples deposited at high gravity condition is higher than the samples deposited at low gravity condition. The impedances and capacitance sensitivities of the of the samples deposited under high gravity condition are 6.1 times and 1.6 times higher than the films deposited under low gravity condition.

关键词： orange dye sensor composite impedance capacitance

Surface-type nonvolatile electric memory elements based on organic-on-organic CuPc-H_2Pc heterojunction

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第11期24卷 328-332页

作者： Khasan S.Karimov Zubair Ahmad Farid Touati m.mahroof-tahir m.muqeet Rehman S.Zameer Abbas Ghulam Ishaq Khan Institute of Engineering Science and Technology Center for Innovative Development of Science and New Technologies Department of Electrical Engineering College of Engineering Qatar University Department of Chemistry and Earth Sciences Qatar University

A novel surface-type nonvolatile electric memory elements based on organic semiconductors CuPc and H2Pc are fabricated by vacuum deposition of the CuPc and H2Pc films on preliminary deposited metallic （Ag and Cu） electrodes. The gap between Ag and Cu electrodes is 3040μm. For the current-voltage （I-V） characteristics the memory effect, switching effect, and negative differential resistance regions are observed. The switching mechanism is attributed to the electric-field-induced charge transfer. As a result the device switches from a low to a high-conductivity state and then back to a low conductivity state if the opposite polarity voltage is applied. The ratio of resistance at the high resistance state to that at the low resistance state is equal to 120-150. Under the switching condition, the electric current increases -- 80-100 times. A comparison between the forward and reverse I-V characteristics shows the presence of rectifying behavior.

关键词： heterojunction nonvolatile memory organic-on-organic CuPc H2Pc

Temperature sensor based on composite film of vanadium complex(VO_2(3-fl))and CNT

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2015年第7期36卷 34-38页

作者： Kh.S.Karimov m.mahroof-tahir m.Saleem m.Tariq Saeed Chani A.Khan Niaz GIK Institute of Engineering Sciences and Technology Center for Innovative Development of Science and New Technologies Academy of Sciences Department of Chemistry and Earth Sciences Qatar University Government College of Science Center of Excellence for Advanced materials Research (CEAmR) King Abdulaziz University

A vanadium complex （VO2（3-fl）） and CNT composite film based temperature sensor is reported in this study. Surface-type silver electrodes were deposited on the glass substrates. A thin film of VOE（3-fl） and CNT composite was coated as a temperature-sensing material on the top of the pre-patterned Ag electrodes. The temperature-sensing principle of the sensor was based on the conductivity change of the coated sensing element upon heating or cooling processes. DC and AC （100 Hz） resistances of the temperature sensor decreased quasi- linearly with increasing the temperature in the range of 25-80 ℃. The overall resistance of the sensor decreases by 1.8-2.1 and 1.9-2.0 times at DC and AC voltage, respectively. The resistance temperature coefficients of the sensor were in the range of-（0.9-1.3）% and -（1.1-1.3）% at DC and AC voltage, respectively. The properties of the sensor studied in this work, make it beneficial to be used in the instruments for environmental monitoring of temperature.

关键词： CNT vanadium complex film temperature sensor resistance

Humidity sensitive organic field effect transistor

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第5期31卷 40-44页

作者： I.murtaza Kh S.Karimov Zubair Ahmad I.Qazi m.mahroof-tahir T.A.Khan T.Amin Ghulam Ishaq Khan Institute of Engineering Sciences and Technology TopiSwabiNWFP23640Pakistan Physical Technical Institute of Academy of Sciences Dushanbe 734025Tajikistan St.Cloud State University MN 56301-4498USA

This paper reports the experimental results for the humidity dependent properties of an organic field effect *** organic field effect transistor was fabricated on thoroughly cleaned glass substrate,in which the junction between the metal gate and the organic channel plays the role of gate *** films of organic semiconductor copper phthalocynanine（CuPc） and semitransparent Al were deposited in sequence by vacuum thermal evaporation on the glass substrate with preliminarily deposited Ag source and drain *** output and transfer characteristics of the fabricated device were *** effect of humidity on the drain current,drain current-drain voltage relationship, and threshold voltage was *** was observed that humidity has a strong effect on the characteristics of the organic field effect transistor.

关键词： organic field effect transistor CuPc metal-semiconductor Schottky junction humidity sensor

Resistive humidity sensor based on vanadium complex films

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2014年第9期35卷 35-38页

作者： Kh.S.Karimov m.Saleem m.mahroof-tahir R.Akram m.T.Saeed Chanee A.K.Niaz GIK Institute of Engineering Sciences and Technology Topi-23640 District Swabi KPK Pakistan Physical Technical Institute of Academy of Sciences Rudaki Ave.33 Dushanbe 734025 Tajikistan Government College of Science Wahdat Road Lahore-54570 Pakistan Saint Cloud State University 720 Fourth Avenue South Saint Cloud MN 56301-4498 USA Center of Excellence for Advanced materials Research (CEAmR) King Abdul Aziz University Jeddah 21589 P.O.Box 80203 Saudi Arabia

A resistive-type relative humidity （RH） sensor based on vanadium complex （VO2（3-f[）） film is reported in this study. Gold electrodes were deposited on the glass substrates in a co-planar structure. A thin film of vanadium complex was coated as a humidity-sensing material on the top of the pre-patterned electrodes. The humidity-sensing principle of the sensor was based on the conductivity change of coated sensing element upon adsorption/desorption of water vapor. The resistance of the humidity sensor measured at 1 kHz decreased linearly with increasing the humidity in the range of 35%-70% RH. The overall resistance of the sensor decreases 11 times. An equivalent circuit for the VO2（3-fl） based resistive-type humidity sensor was developed. The properties of the sensor studied in this work make it beneficial for use in the instruments for environmental monitoring of humidity.

关键词： vanadium complex thin film humidity sensor resistance

Source parameters and aftershock pattern of the October 7,2021,m5.9 Harnai earthquake,Pakistan

在线全文

学校读者我要写书评

暂无评论

Earthquake Science 2024年第4期37卷 304-323页

作者： mohammad tahir Zeeshan Ahmad Sadia Sabahat muhammad Naveed mushtaq Talat Iqbal muhammad Ali Shah Alam Aftab Centre for Earthquake Studies National Centre for PhysicsIslamabad 44000Pakistan

On October 7,2021,a magnitude 5.9 earthquake struck the Harnai(Baluchistan)region of Pakistan,causing several fatalities and injuries within the epicentral ***-order tectonic deformation in this region is caused by the convergence of the Indian Plate with respect to the Eurasian *** Katwaz Block hinders the motion of the Indian Plate,resulting in the formation of strike-slip *** this study,the P-wave first-motion polarity technique was used to determine the mainshock faulting *** scanning of the polarity solutions was applied to determine the most suitable focal mechanism solution among the available solutions generated by the FOCmEC(focal mechanism)*** nodal planes correspond to different faulting styles(i.e.,thrust and strike-slip faulting).A nodal plane oriented in the NW-SE direction corresponded to a strike-slip mechanism,which was considered to be the fault ***,this earthquake was associated with the Harnai-Karahi strike-slip fault zone owing to the fault strike and direction of *** apparent stress drop,fault length,and moment magnitude of the Harnai earthquake were 35.4 bar,6.1 km,and 5.9,respectively.A lower b-value for the Gutenberg-Richter law was observed prior to the ***α-than b-values(α>b)indicate that this earthquake was governed by large events as opposed to small-magnitude *** Harnai sequence had a decay exponent close to unity,lasted for 145 days,and produced few *** study will help the future hazard mitigation in the region.

关键词： focal mechanism solution selection of fault plane FPFIT stress inversion oblique slip mechanism

Analysis of cerium substitution in Co-Sr based spinel ferrites for high frequency application

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第9期42卷 1755-1763,I0005页

作者： Laura Khudaysh Inas A.Ahmed Syeda Rabia Ejaz Sajjad Ahmad Khan Yasir A.Haleem mohamed m.Ibrahim mahmood Ali Hafiz muhammad tahir Farid Zeinhom m.El-Bahy Department of Physics Faculty of ScienceJazan UniversityJazan45142Saudi Arabia Department of Chemistry Faculty of ScienceKing Khalid UniversityAbha62224Saudi Arabia Department of Physics The Government Sadiq College Women UniversityBahawalpur63100Pakistan Institute of Physics Khwaja Fareed University of Engineering and Information TechnologyRahim Yar Khan64200Pakistan Department of Chemistry College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Centre of Excellence in Solid State Physics University of the PunjabLahorePakistan Department of Physics Government CollegeTaunsa Sharif32200Pakistan Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt

Spinel ferrites exhibit exceptional magnetic properties,making them a distinctive class of magnetic *** sol-gel technique was utilized for the synthesis of spinel ferrites with the chemical formula Co_(0.6)Sr_(0.4)Ce_(x)Fe_(2-x)O_(4). Following that,a comprehensive X-ray diffraction analysis unveiled the crystalline cubic structure of the synthesized *** the utilization of the m-H loop approach,the ferromagnetic attributes of ferrites were assessed,and the assimilation of rare earth elements led to substantial enhancements in saturation magnetization,remanence,and *** ferrites with a high concentration of rare earth elements have improved direct current resistivity and activation *** logarithm of a material's resistance increased from 5.29 to 8.12 Ω·cm as cerium is *** a change in the amount of cerium,the activation energy goes up from 0.19 to *** changing the frequency from 5.5 to 9.5 GHz,the dielectric characteristics were *** the frequency goes up,the dielectric constant goes *** ferrites that have been made better in every way can be used in high-frequency applications.

关键词： Activation energy DC electrical resistance Remanence magnetization Cobalt strontium spinel ferrites High frequency application Rare earths

Interdigital mnO_(2)/PEDOT Alternating Stacked microelectrodes for High-Performance On-Chip microsupercapacitor and Humidity Sensing

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental materials 2024年第2期7卷 257-267页

作者： muhammad tahir Lihong Li Liang He Zhongyuan Xiang Zeyu ma Waqas Ali Haider Xiaoqiao Liao Yanlin Song Key Laboratory of Green Printing CAS Research/Education Centre for Excellence in Molecular SciencesInstitute of Chemistry Chinese Academy of Sciences(ICCAS)Beijing 100190China School of mechanical Engineering Sichuan UniversityChengdu 610065China A.S.Chemical Laboratories Inc. Concord L4K 4M4ON Canada

For microelectronic devices,the on-chip microsupercapacitors with facile construction and high performance,are attracting researchers'prior consideration due to their high compatibility with modern ***,we proposed interchanging interdigital Au-/mnO_(2)/polyethylene dioxythiophene stacked microsupercapacitor based on a microfabrication process followed by successive electrochemical *** stacked configuration of two pseudocapacitive active microelectrodes meritoriously leads to an enhanced contact area between mnO_(2)and the conductive and electroactive layer of polyethylene dioxythiophene,hence providing excellent electron transport and diffusion pathways of electrolyte ions,resulting in increased pseudocapacitance of mnO_(2)and polyethylene *** stacked quasi-solid-state microsupercapacitors delivered the maximum specific capacitance of 43 mF cm^(-2)(211.9 F cm^(-3)),an energy density of 3.8μWh cm^(-2)(at a voltage window of 0.8 V)and 5.1μWh cm^(-2)(at a voltage window of 1.0 V)with excellent rate capability(96.6%at 2 mA cm^(-2))and cycling performance of 85.3%retention of initial capacitance after 10000 consecutive cycles at a current density of 5 mA cm^(-2),higher than those of ever reported polyethylene dioxythiophene and mnO_(2)-based planar *** from the favorable morphology,bilayer microsupercapacitor is utilized as a flexible humidity sensor with a response/relaxation time superior to those of some commercially available integrated *** strategy will be of significance in developing high-performance on-chip integrated microsupercapacitors/microsensors at low cost and environment-friendly routes.

关键词： electrochemical polymerization microsensor microsupercapacitor stacked microelectrode

Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction

在线全文

学校读者我要写书评

暂无评论

World Journal of Transplantation 2024年第1期14卷 154-163页

作者： Ameet Kumar Jesrani Syed m Faiq Rahma Rashid Tariq Ali Kalwar Rehan mohsin tahir Aziz Nida Amin Khan muhammed mubarak Department of Radiology Sindh Institute of Urology and TransplantationKarachi 74200SindhPakistan Department of Pathology Sindh Institute of Urology and TransplantationKarachi 74200SindhPakistan Department of Transplantation Sindh Institute of Urology and TransplantationKarachi 74200SindhPakistan Department of Urology Sindh Institute of Urology and TransplantationKarachi 74200SindhPakistan

BACKGROUND Detection of early chronic changes in the kidney allograft is important for timely intervention and long-term *** and novel ultrasound-based investigations are being increasingly used for this purpose with variable *** To compare the diagnostic performance of resistive index(RI)and shear wave elastography(SWE)in the diagnosis of chronic fibrosing changes of kidney allograft with histopathological *** This is a cross-sectional and comparative study.A total of 154 kidney transplant recipients were included in this study,which was conducted at the Departments of Transplantation and Radiology,Sindh Institute of Urology and Transplantation,Karachi,Pakistan,from August 2022 to February *** consecutive patients with increased serum creatinine levels and reduced glomerular filtration rate(GFR)after three months of transplantation were enrolled in this *** and RI were performed and the findings of these were evaluated against the kidney allograft biopsy results to determine their diagnostic *** The mean age of all patients was 35.32±11.08 *** these,126(81.8%)were males and 28(18.2%)were *** mean serum creatinine in all patients was 2.86±1.68 mg/dL and the mean estimated GFR was 35.38±17.27 mL/min/1.73 *** allograft biopsy results showed chronic changes in 55(37.66%)*** sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of SWE for the detection of chronic allograft damage were 93.10%,96.87%%,94.73%,and 95.87%,respectively,and the diagnostic accuracy was 95.45%.For RI,the sensitivity,specificity,PPV,and NPV were 76.92%,83.33%,70.17%,and 87.62%,respectively,and the diagnostic accuracy was 81.16%.CONCLUSION The results from this study show that SWE is more sensitive and specific as compared to RI in the evaluation of chronic allograft *** can be of great help during the routine follow-up of kidney transplant recipients for screening a

关键词： Shear wave Sonoelastography Resistive index Chronic allograft changes Biopsy Histopathology