60 research outputs found

    Consumers’ Attitude and Preference toward Fresh Tomatoes in Special Region of Yogyakarta, Indonesia

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    Increasing tomatoes consumption which is driven by needs and desires, changes consumers’ tastes and preferences. This study aimed to determine consumers’ attitudes and preferences towards tomato’s attributes. A convenience sampling which consisted of 150 respondents in the Special Region of Yogyakarta was selected for this research. Fishbein’s Multi-attribute was used to analyze consumers’ attitude, and a conjoint analysis was employed to identify consumers’ preferences. According to the findings of this study, consumers have a favorable attitude toward tomato attributes such as freshness, color, firm texture, surface appearance, and taste. Meanwhile, the findings of the conjoint analysis revealed that the color of the tomatoes was the most favored characteristic. The most preferred combination of tomato characteristics was red color, highly fresh, firm texture, spot-free surface look, and sweetness

    Pregnancy-associated breast cancer: A review of imaging modalities

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    Context: The most common cancer and cause of cancer-related death in pregnant and breastfeeding patients is breast cancer. In the world, the incidence of pregnancy-associated breast cancer (P.A.B.C) is increasing, which is due to the fact that women delay their pregnancy up to the middle ages. According to the definition of P.A.B.C, a pregnancy-associated breast cancer is a case of breast cancer that occurs during pregnancy or up to 1 year after delivery. The aim of this paper is to review the clinical findings and novel imaging methods and findings, which help to diagnose pregnancy-associated breast cancer early. Evidence Acquisition: We reviewed the papers with subjects of PABC and imaging modalities in PABC by searching the medical and health databases such as PubMed, Google Scholar, as well as clinical trials. Results: The most frequent manifestation is a painless mass sensation. The most prevalent pathology of PABC is high-grade ductal carcinoma. The first diagnostic tool and most sensitive modality of imaging in this disease is ultrasound. Mammography during pregnancy and lactation is a safe method, which performs in symptomatic patients or in patients with positive ultrasound findings. MRI is not recommended during pregnancy, but it is completely harmless in breastfeeding patients and it is usually used as the complementary modality. Conclusions: Timely diagnosis of PABC requires complete knowledge of clinical symptoms and accurate interpreting of the images in different diagnostic modalities including mammography, ultrasound, and MRI. It should be noted that delay in diagnosis of PABC is the most common cause of low survival rate and bad prognosis. © 2018, Author(s)

    Characterization of germanium/silicon p-n junction fabricated by low temperature direct wafer bonding and layer exfoliation

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    The current transport across a p-Ge/n-Si diode structure obtained by direct wafer bonding and layer exfoliation is analysed. A low temperature anneal at 400 degrees C for 30 min was used to improve the forward characteristics of the diode with the on/off ratio at -1 V being > 8000. Post anneal, the transport mechanism has a strong tunnelling component. This fabrication technique using a low thermal budget (T <= 400 degrees C) is an attractive option for heterogeneous integration. (C) 2012 American Institute of Physics. (doi:10.1063/1.3688174

    Assessment of ultrasound features and BI-RADS categories of malignant breast masses in Women � 40

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    Background: To evaluate ultrasound (US) characteristics and BI-RADS (Breast imaging-reporting and data system) of malignant breast masses in women <40 years and to compare with older patients. Methods: In a retrospective, descriptive-analytical study, we assessed the US images and BI-RADS category of 78 malignant masses with a final pathology of invasive ductal carcinoma (IDC, NOS type). Results: Overall, the most frequent US descriptors of IDC were indistinct margin (45), irregular shaped (63.5), posterior shadowing (38.8), heterogeneous internal echogenicity (56.3) and non-parallel orientation (76.3). In this study, most malignant masses of young patients were categorized as BI-RADS 4a while in the older patients (over 40), they were mostly BI-RADS 4b and 5 with P=0.03 and odds ratio (OR) of 2.57 (95 confidence interval (CI), 0.74-8.8). In addition, the mean dimension of the mass in young cases was greater (18.3 mm) compared with older patients (13.2 mm) with P value of 0.04 and OR of 3.8 (95 CI, 1.1-13.4). Conclusion: Similar to previous studies, malignant masses were diagnosed in greater dimensions in younger cases which may be due to the delay in diagnosis, the rapid growth of the tumor and the absence of routine screening guidelines. Radiologists should be aware of the possibility of malignancy in palpable slightly suspicious masses (BI-RADS 4A) in young cases. © 2021 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Experimental analysis of variability in WS2_2-based devices for hardware security

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    This work investigates the variability of tungsten disulfide (WS2_2)-based devices by experimental characterization in view of possible application in the field of hardware security. To this aim, a preliminary analysis was performed by measurements across voltages and temperatures on a set of seven Si/SiO2_2/WS2_2 back-gated devices, also considering the effect of different stabilization conditions on their conductivity. Obtained results show appreciable variability in the conductivity, while also revealing similar dependence on bias and temperature across tested devices. Overall, our analysis demonstrates that WS2_2-based devices can be potentially exploited to ensure adequate randomness and robustness against environmental variations and then used as building blocks for hardware security primitives

    Air sensitivity of MoS2, MoSe2, MoTe2, HfS2 and HfSe2

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    A surface sensitivity study was performed on different transition-metal dichalcogenides (TMDs) under ambient conditions in order to understand which material is the most suitable for future device applications. Initially, Atomic Force Microscopy and Scanning Electron Microscopy studies were carried out over a period of 27 days on mechanically exfoliated flakes of 5 different TMDs, namely, MoS2, MoSe2, MoTe2, HfS2, and HfSe2. The most reactive were MoTe2 and HfSe2. HfSe2, in particular, showed surface protrusions after ambient exposure, reaching a height and width of approximately 60 nm after a single day. This study was later supplemented by Transmission Electron Microscopy (TEM) cross-sectional analysis, which showed hemispherical-shaped surface blisters that are amorphous in nature, approximately 180–240 nm tall and 420–540 nm wide, after 5 months of air exposure, as well as surface deformation in regions between these structures, related to surface oxidation. An X-ray photoelectron spectroscopy study of atmosphere exposed HfSe2 was conducted over various time scales, which indicated that the Hf undergoes a preferential reaction with oxygen as compared to the Se. Energy-Dispersive X-Ray Spectroscopy showed that the blisters are Se-rich; thus, it is theorised that HfO2 forms when the HfSe2 reacts in ambient, which in turn causes the Se atoms to be aggregated at the surface in the form of blisters. Overall, it is evident that air contact drastically affects the structural properties of TMD materials. This issue poses one of the biggest challenges for future TMD-based devices and technologies

    The effect of interfacial charge on the development of wafer bonded silicon-on-silicon-carbide power devices

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    A new generation of power electronic semiconductor devices are being developed for the benefit of space and terrestrial harsh-environment applications. 200-600 V lateral transistors and diodes are being fabricated in a thin layer of silicon (Si) wafer bonded to semi-insulating 4H silicon carbide (SiC) leading to a Si/SiC substrate solution that promises to combine the benefits of silicon-on-insulator (SOI) technology with that of SiC. Here, details of a process are given to produce thin films of silicon 1 and 2 μm thick on the SiC. Simple metal-oxide-semiconductor capacitors (MOS-Cs) and Schottky diodes in these layers revealed that the Si device layer that had been expected to be n-type, was now behaving as a p-type semiconductor. Transmission electron microscopy (TEM) of the interface revealed that the high temperature process employed to transfer the Si device layer from the SOI to the SiC substrate caused lateral inhomogeneity and damage at the interface. This is expected to have increased the amount of trapped charge at the interface, leading to Fermi pinning at the interface, and band bending throughout the Si layer

    Thermal characterization of direct wafer bonded Si-on-SiC

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    Direct bonded Si-on-SiC is an interesting alternative to silicon-on-insulator (SOI) for improved thermal management in power conversion and radio frequency applications in space. We have used transient thermoreflectance and finite element simulations to characterize the thermal properties of direct bonded Si-on-4H–SiC samples, utilizing a hydrophobic and hydrophilic bonding process. In both instances, the interface has good thermal properties resulting in TBReff values of 6 + 4/−2 m2 K GW−1 (hydrophobic) and 9 + 3/−2 m2 K GW−1 (hydrophilic). Two-dimensional finite element simulations for an equivalent MOSFET showed the significant thermal benefit of using Si-on-SiC over SOI. In these simulations, a MOSFET with a 200 nm thick, 42 μm wide Si drift region was recreated on a SOI structure (2 μm buried oxide) and on the Si-on-SiC material characterized here. At 5 W mm−1 power dissipation, the Si-on-SiC was shown to result in a &gt;60% decrease in temperature rise compared to the SOI structure

    Structural and electronic properties of polycrystalline InAs thin films deposited on silicon dioxide and glass at temperatures below 500 °c

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    Polycrystalline indium arsenide (poly InAs) thin films grown at 475 °C by metal organic vapor phase epitaxy (MOVPE) are explored as possible candidates for low-temperature-grown semiconducting materials. Structural and transport properties of the films are reported, with electron mobilities of ~100 cm2/V·s achieved at room temperature, and values reaching 155 cm2/V·s for a heterostructure including the polycrystalline InAs film. Test structures fabricated with an aluminum oxide (Al2O3) top-gate dielectric show that transistor-type behavior is possible when poly InAs films are implemented as the channel material, with maximum ION/IOFF > 250 achieved at −50 °C and ION/IOFF = 90 at room temperature. Factors limiting the ION/IOFF ratio are investigated and recommendations are made for future implementation of this material

    Influence of free radical surface activation on Si/SiC heterogeneous integration by direct wafer bonding

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    In this study, a surface activated bonding method using remote plasma is applied to realize the direct wafer bonding of Si and SiC. A comparison of different surface treatments is reported. Hydrophilic and hydrophobic wafers have been exposed to in-situ argon and nitrogen radicals generated by remote plasma for surface activation before bonding. A comparison of the bonding yield and surface condition has been conducted and analyzed as a function of the surface treatments. It has been shown that N2 plasma leads to the highest yield of > 97 %, strongest bond of > 360 N and interfacial layer (IL) thickness of ~1.5 nm
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