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Article ; Online: Solar thermionic energy converters with micro-gap spacers.

Zhang, Xin / Rahman, Ehsanur

Optics letters

2023 Volume 48, Issue 15, Page(s) 4173–4176

Abstract: We present a solar thermionic energy converter (STEC) incorporating interelectrode spacer structures for solar energy harvesting. We demonstrate the impact of spacer loss on the optimal performance and gap size of STECs with and without interelectrode ... ...

Abstract	We present a solar thermionic energy converter (STEC) incorporating interelectrode spacer structures for solar energy harvesting. We demonstrate the impact of spacer loss on the optimal performance and gap size of STECs with and without interelectrode spacers. Under a solar concentration factor of 100, we show that the maximum efficiency of STECs with a spacer (5.3%) is significantly lower than that of STECs without a spacer (8.7%) at different optimal gaps due to the interelectrode spacer that conducts heat parasitically. The optimal gap ranges from a few tenths of a micron to a few microns for STECs without spacers, while the optimal gap is around 8
Language	English
Publishing date	2023-07-28
Publishing country	United States
Document type	Journal Article
ISSN	1539-4794
ISSN (online)	1539-4794
DOI	10.1364/OL.498374
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Solar thermionic energy converters with micro-gap spacers: publisher's note.

Zhang, Xin / Rahman, Ehsanur

Optics letters

2023 Volume 48, Issue 17, Page(s) 4549

Abstract: This publisher's note contains corrections to Opt. Lett.48, 4173 (2023)10.1364/OL.498374. ...

Abstract	This publisher's note contains corrections to Opt. Lett.48, 4173 (2023)10.1364/OL.498374.
Language	English
Publishing date	2023-07-15
Publishing country	United States
Document type	Journal Article
ISSN	1539-4794
ISSN (online)	1539-4794
DOI	10.1364/OL.502667
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Article ; Online: Semiconductor thermionics for next generation solar cells: photon enhanced or pure thermionic?

Rahman, Ehsanur / Nojeh, Alireza

Nature communications

2021 Volume 12, Issue 1, Page(s) 4622

Abstract: Semiconductors have been used in solar energy conversion for decades based on the photovoltaic effect. An important challenge of photovoltaics is the undesired heat generated within the device. An alternative approach is thermionics, which uses the ... ...

Abstract	Semiconductors have been used in solar energy conversion for decades based on the photovoltaic effect. An important challenge of photovoltaics is the undesired heat generated within the device. An alternative approach is thermionics, which uses the thermal excitation of electrons from an emitter to a collector across a vacuum gap. If the emitter is a p-type semiconductor, the photogeneration-induced quasi-Fermi level splitting can reduce the effective barrier for electron emission-a mechanism used by a photon enhanced thermionic emission device. Here, we evaluate the prospects of this alternative solar conversion technology considering different semiconductor materials and thermionic device configurations. We also reveal that whether such a device operates in the photon enhanced or purely thermionic mode, depends on the complex interplay among materials properties, device physics and solar concentration level.
Language	English
Publishing date	2021-07-30
Publishing country	England
Document type	Journal Article
ZDB-ID	2553671-0
ISSN	2041-1723 ; 2041-1723
ISSN (online)	2041-1723
ISSN	2041-1723
DOI	10.1038/s41467-021-24891-2
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Effect of vacancy defects on the electronic and mechanical properties of two-dimensional MoSi

Dastider, Ankan Ghosh / Rasul, Ashiqur / Rahman, Ehsanur / Alam, Md Kawsar

RSC advances

2023 Volume 13, Issue 8, Page(s) 5307–5316

Abstract: ... ...

Abstract	MoSi
Language	English
Publishing date	2023-02-10
Publishing country	England
Document type	Journal Article
ISSN	2046-2069
ISSN (online)	2046-2069
DOI	10.1039/d2ra07483d
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Article: Upgrade Rate of Ductal Carcinoma In Situ to Invasive Carcinoma and the Clinicopathological Factors Predicting the Upgrade Following a Mastectomy: A Retrospective Study.

Al-Ishaq, Zaid / Hajiesmaeili, Hamed / Rahman, Ehsanur / Khosla, Muskaan / Sircar, Tapan

Cureus

2023 Volume 15, Issue 3, Page(s) e35735

Abstract: Background The rate of upgrading ductal carcinoma in situ (DCIS) to invasive cancer varies widely in the literature with no consensus regarding sentinel lymph node biopsy (SLNB) for DCIS; however, some guidelines do recommend it in the event of a ... ...

Abstract	Background The rate of upgrading ductal carcinoma in situ (DCIS) to invasive cancer varies widely in the literature with no consensus regarding sentinel lymph node biopsy (SLNB) for DCIS; however, some guidelines do recommend it in the event of a mastectomy. The primary aim of this study was to determine the upgrade rate of DCIS to invasive carcinoma (IC) in patients undergoing mastectomy for DCIS and identify the clinicopathological predicting factors for the upgrade. The secondary aim was to determine the SLNB positivity rate. Methodology We retrospectively analysed consecutive patients with DCIS diagnosed through a biopsy who then underwent mastectomy over a 10-year period (2010 to 2020). Clinical, radiological, and histological variables were collected from medical records. Results We studied 143 women (mean age = 57.4 years, range = 26-85 years) who underwent mastectomy for DCIS identified on biopsy. Almost two-thirds (62.9%, 90/143) of the patients were detected on screening mammography, while 35.6% (51/143) were diagnosed following presentation with either an area of palpable concern or nipple discharge. The most common mammographic presentation of DCIS was calcification (83.9%, 120/143), and, in 85.9% of the patients, the mammographic lesion was more than 20 mm. High-grade DCIS was noted in 76.9% of preoperative biopsy results, while the rest was either low or intermediate-grade DCIS. Overall, 24.5% (35/143) were upgraded to IC (upgraded group) on postoperative histology, whereas 108/143 remained DCIS postoperatively (pure DCIS group). The positivity rate of SLNB was 4.8%. Multifocality was the only significant predictor of IC on multivariate analyses of clinicopathological predictors (odds ratio = 3.0, 95% confidence interval = 1.0-8.7). The presence of comedonecrosis was higher in the upgraded group compared to the pure DCIS group (42.9% vs. 27.8%), but this was not statistically significant. Conclusions In our study cohort, nearly one in four (24.5%) patients were upgraded from DCIS to IC on postoperative histology, with an SLNB positivity rate of 4.8%. This is important when counselling patients regarding the risk of coincident occult IC and the importance of SLNB at the time of mastectomy. Multifocality on preoperative imaging was the only significant predictive factor. Based on this result, we recommend that SLNB should also be considered if patients have multifocal DCIS and planned for oncoplastic breast-conserving surgery. However, further studies are required to investigate the association between multifocal DCIS and the risk of upgrading to IC.
Language	English
Publishing date	2023-03-03
Publishing country	United States
Document type	Journal Article
ZDB-ID	2747273-5
ISSN	2168-8184
ISSN	2168-8184
DOI	10.7759/cureus.35735
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Article: Efficacy of neck muscle activation versus strengthening for adults with chronic cervical radiculopathy: a study protocol for a randomised clinical trial.

Sharmin, Farzana / Hossain, K M Amran / Kabir, Feroz / Hossain, Md Zahid / Jahan, Sharmila / Rahman, Ehsanur / Islam, Md Aminul

BMJ open sport & exercise medicine

2024 Volume 10, Issue 1, Page(s) e001819

Abstract: Introduction: Chronic cervical radiculopathy is a common condition characterised by neck and arm pain, numbness and weakness. Both neck muscle activation and strengthening exercises are widely recognised treatments for cervical radiculopathy, but there ... ...

Abstract	Introduction: Chronic cervical radiculopathy is a common condition characterised by neck and arm pain, numbness and weakness. Both neck muscle activation and strengthening exercises are widely recognised treatments for cervical radiculopathy, but there is a research gap on the efficacy of neck muscle activation versus strengthening. This protocol will determine the efficacy of neck muscle activation alongside conventional care versus strengthening exercise and conventional care for cervical radiculopathy. Methods and analysis: We planned a 5-week parallel, two-arm randomised clinical trial on 80 participants with chronic cervical radiculopathy (lasting over 3 months) between July and December 2023. Participants will be recruited from Dhaka's Agrani Specialised Physiotherapy Centre in Bangladesh and randomly assigned to two groups in a 1:1 ratio. Both groups will receive 14 sessions, each lasting 30-45 min. Post-treatment evaluations will be employed on Brief Pain Inventory (BPI), range of motion, craniovertebral angle (CVA), strength, endurance and Neck Disability Index (NDI) after 5 weeks and follow-up after 12 weeks of post-test analysis. Primary outcomes (strength, endurance and CVA) will be measured using a handheld dynamometer, digital inclinometer and goniometer. Secondary outcomes (pain, range of motion and disability) will be assessed through the BPI scale, digital inclinometer and NDI. Ethics and dissemination: The Institute of Physiotherapy Rehabilitation and Research of Bangladesh Physiotherapy Association has approved the study. All participants will provide informed consent, and data will be anonymised and accessible only to authorised personnel. The study's findings will be disseminated in peer-reviewed journals and conferences. Clinical trial registry india: CTRI/2023/09/057587 (13/09/2023).
Language	English
Publishing date	2024-02-14
Publishing country	England
Document type	Journal Article
ZDB-ID	2817580-3
ISSN	2055-7647
ISSN	2055-7647
DOI	10.1136/bmjsem-2023-001819
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Article ; Online: Adsorbate-enhanced field-emission from single-walled carbon nanotubes: a comparative first-principles study.

Rahman, Ehsanur / Nojeh, Alireza

Nanotechnology

2019 Volume 30, Issue 17, Page(s) 175202

Abstract: We report a comparative ab initio study of different types of adsorbates and their adsorption mechanism on the field-emission performance of single-walled carbon nanotubes by analyzing electrical properties and transport characteristics and considering ... ...

Abstract	We report a comparative ab initio study of different types of adsorbates and their adsorption mechanism on the field-emission performance of single-walled carbon nanotubes by analyzing electrical properties and transport characteristics and considering the thermal stability of the adsorbed structure. Adsorbates were found to reduce the work function by up to 1.3 eV, enhance tunneling near the carbon nanotube tip, and increase the field-emission current by as much as two orders of magnitude. A significant localization of the electron cloud was also observed near the adsorbates under a high applied electric field.
Language	English
Publishing date	2019-01-17
Publishing country	England
Document type	Journal Article
ZDB-ID	1362365-5
ISSN	1361-6528 ; 0957-4484
ISSN (online)	1361-6528
ISSN	0957-4484
DOI	10.1088/1361-6528/aaff94
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Article ; Online: Effectiveness of a novel consultant nurse-led breast pain clinic in secondary care.

Al-Ishaq, Zaid / Taj, Saima / Jones, Caroline / Hajiesmaeli, Hamed / Rahman, Ehsanur / Bullows, Samantha / Vidya, Raghavan / Sircar, Tapan

Irish journal of medical science

2024

Abstract: Background: Patients with breast pain are usually seen in 'one-stop clinic' (OSC) with breast imaging. In the absence of associated red flag features, the incidence of breast cancer is extremely low. With increase in referrals the OSC capacity is over- ... ...

Abstract	Background: Patients with breast pain are usually seen in 'one-stop clinic' (OSC) with breast imaging. In the absence of associated red flag features, the incidence of breast cancer is extremely low. With increase in referrals the OSC capacity is over-stretched. We developed a consultant nurse-led dedicated 'breast pain clinic' in September 2021 without routine breast imaging. After meticulous history and examination, patients obtained detailed counselling and advice regarding breast pain management. If any abnormality was noted then appointment was given for OSC. Aim: To assess the effectiveness of a consultant nurse-led dedicated 'breast pain clinic'. Methods: A prospective study of all consecutive patients seen in 'breast pain clinic' from September 2021 until September 2022. Feedback was sought from all patients. Results: Altogether 429 patients were seen. The mean age was 48.7 years (range 18-86). 87.6% (n = 376) patients required no breast imaging. Only 12.4% (n = 53) patients needed referral to OSC and subsequently 2 patients (0.46%) were diagnosed with breast cancer. Ninety-eight percent of patients felt reassured and 99.2% patients were extremely likely/likely to recommend this service to family and friends. Out of 376 patients who were discharged from breast pain clinic, 12 patients were referred again over a median follow-up period of 15 months, and 2 out of them were diagnosed with breast cancer. Conclusion: A consultant nurse-led 'breast pain clinic' provides service improvement as it eases the pressure on the OSC. Most patients were managed without breast imaging with high level of patient satisfaction and low rereferral rate.
Language	English
Publishing date	2024-02-26
Publishing country	Ireland
Document type	Journal Article
ZDB-ID	390895-1
ISSN	1863-4362 ; 0021-1265
ISSN (online)	1863-4362
ISSN	0021-1265
DOI	10.1007/s11845-024-03642-4
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article: A critical review of the emerging research on the detection and assessment of microplastics pollution in the coastal, marine, and urban Bangladesh

Pushan, Zaki Alam / Rahman, Ehsanur / Islam, Nafisa / Aich, Nirupam

Frontiers of environmental science & engineering. 2022 Oct., v. 16, no. 10

2022

Abstract: The research on the extent and effects of microplastics pollution in the Global South is only getting started. Bangladesh is a South Asian country with one of the fastest growing economies in the world, however, such exponential economic growth has also ... ...

Abstract	The research on the extent and effects of microplastics pollution in the Global South is only getting started. Bangladesh is a South Asian country with one of the fastest growing economies in the world, however, such exponential economic growth has also increased the pollution threats to its natural and urban environment. In this paper, we reviewed the recent primary research on the assessment of the extent of microplastics pollution in Bangladesh. From the online databases, we developed a compilation of emerging research articles that detected and quantified microplastics in different coastal, marine, and urban environments in Bangladesh. Most of the studies focused on the coastal environment (e.g., beach sediment) and marine fish, while limited data were available for the urban environment. We also discussed the relationship of the type of anthropogenic activities with the observed microplastic pollution. The Cox’s Bazar sea beach in south-east Bangladesh experienced microplastics pollution due to tourism activities, while fishing and other anthropogenic activities led to microplastics pollution in the Bay of Bengal. While microplastics larger than 1 mm were prevalent in the beach sediments, smaller microplastics with size below 0.5 mm were prevalent in marine fish samples. Moreover, the differences in microplastic abundance, size, shape, color, and polymer type found were depended on the sampling sites and relevant anthropogenic activities. It is imperative to identify major sources of microplastics pollution in both natural and urban environment, determine potential environmental and human health effects, and develop mitigating and prevention strategies for reducing microplastics pollution.
Keywords	color ; economic development ; human health ; marine fish ; microplastics ; pollution ; sediments ; tourism ; urban areas ; Bangladesh ; Bay of Bengal
Language	English
Dates of publication	2022-10
Size	p. 128.
Publishing place	Higher Education Press
Document type	Article
Note	Review
ZDB-ID	2662203-8
ISSN	2095-221X ; 2095-2201
ISSN (online)	2095-221X
ISSN	2095-2201
DOI	10.1007/s11783-022-1563-2
Database	NAL-Catalogue (AGRICOLA)

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Book ; Online: Interplay Between Near-Field Radiative Coupling and Space Charge Effects in a Micro gap Thermionic Energy Converter under Fixed Heat Input

Rahman, Ehsanur / Nojeh, Alireza

2020

Abstract: We investigate the performance of a micro gap vacuum thermionic energy converter considering the loss mechanisms due to the space charge effect and interelectrode radiative heat transfer. The dependencies of the space charge effect and near-field ... ...

Abstract	We investigate the performance of a micro gap vacuum thermionic energy converter considering the loss mechanisms due to the space charge effect and interelectrode radiative heat transfer. The dependencies of the space charge effect and near-field radiative heat exchange on the interelectrode distance are derived based on established theories. The electrode temperatures are determined by solving the steady-state energy balance equations in a numerical, iterative process and considering a constant energy flux input to the emitter. The resultant behaviour of the different mechanisms of energy flow from the electrodes is studied for a wide range of interelectrode distances, which provides new insights into the device operation. The maximum efficiency of the converter is obtained by optimizing the operating voltage and interelectrode distance. Considering the interplay between space charge and near-field radiative heat transfer, an optimal range is determined for the interelectrode distance. The optimal value of the distance and the lower limit of this range are found to be significantly higher than previously reported, where constant electrode temperatures had been assumed. Comment: 32 pages, 12 figures
Keywords	Physics - Applied Physics ; Electrical Engineering and Systems Science - Signal Processing
Subject code	621
Publishing date	2020-04-30
Publishing country	us
Document type	Book ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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