This issue's article reports on papers from the IEEE 25th International Conference on Software Analysis, Evolution, and Reengineering (SANER 18) and 5th International Conference on Information and ...Communications Technology for Sustainability (ICT4S 18).
Materials best-suited for direct application exhibit a high thermoelectric figure of merit (
ZT
) close to unity, from room temperature to ∼ 400 K. In this work, we investigated the thermoelectric ...behavior of Ag
2
Se, and a sulfur substituted Ag
2
Se system, i.e. Ag
2
S
0.2
Se
0.8
and Ag
2
S
0.4
Se
0.6
, in the temperature range of 300 K to 500 K. With strong anharmonic lattice vibration and semiconducting electronic structure, these materials showed thermal conductivity less than 1 W m
−1
K
−1
, electrical resistivity ∼ 1 mΩ cm, together with moderate Seebeck coefficient values of ∼ − 140
μ
V K
−1
in the low-temperature phase. We were able to achieve
ZT
equal to unity in a wide temperature range of 350–400 K, with a maximum value of
ZT
= 1.08 at 350 K for the Ag
2
S
0.4
Se
0.6
material.
This issue’s article reports from the 40th International Conference on Software Engineering (ICSE 18) and the 17th International Conference on Software Reuse (ICSR 18). The ICSE papers focus on ...sociotechnical issues related to gender and sentiment or emotion. The ICSR paper focuses on safety-critical systems.
ICMN-2K19:“International Conference on Advances in Material Science and Nanotechnology” aims to bring together leading academic scientists, researchers and research scholars to exchange and share ...their experiences. It also provides the premier multidisciplinary forum for researchers, practitioners and educators to present and discuss the most recent innovations, trends, and concerns, practical challenges encountered and the solutions adopted in the field of Emerging Trends in Engineering and Technology.It covers the major areas like Electrical Materials, MEMS and NEMS, Materials, preparation and processing Nanotechnology, Nano Devices, Semiconductor devices.
•We present a model to quickly assess a robustness of a measurement program in industry.•Our method was applied at seven large software development companies.•Measurement programs differ based on the ...development process.
Measurement programs in large software development organizations contain a large number of indicators, base and derived measures to monitor products, processes and projects. The diversity and the number of these measures causes the measurement programs to become large, combining multiple needs, measurement tools and organizational goals. For the measurement program to effectively support organization’s goals, it should be scalable, automated, standardized and flexible – i.e. robust. In this paper we present a method for assessing the robustness of measurement programs. The method is based on the robustness model which has been developed in collaboration between seven companies and a university. The purpose of the method is to support the companies to optimize the value obtained from the measurement programs and their cost. We evaluated the method at the seven companies and the results from applying the method to each company quantified the robustness of their programs, reflecting the real-world status of the programs and pinpointed strengths and improvements of the programs.
This communication presents a novel, low-profile coplanar waveguide (CPW)-fed dual-band microstrip antenna for wireless applications. The proposed antenna consists of an inverted L-shaped slot ...radiator coupled with a U-shaped ground plane and two vertical ground terminals. It is implemented on FR4-epoxy dielectric substrate material (
ε
r
= 4.4, tan
δ
= 0.02) with dimensions of 56 × 56 mm
2
and generates two desired resonant frequencies at about 2.40 GHz and 3.48 GHz for WLAN and WiMAX applications, respectively. The antenna shows two distinct bands, first from 2.34 to 2.54 (200 MHz at −20 dB) and second from 3.25 to 3.60 (350 MHz at −12 dB), which cover the entire WLAN (
f
c
= 2.4 GHz, 2.400–2.484 GHz) and WiMAX (
f
c
= 3.5 GHz, 3.400–3.690 GHz) bands. This work aims to combine WLAN and WiMAX communication standards simultaneously into a single device by designing a single antenna that can excite dual-band operation. Also, numerical findings are presented for the antenna's return loss and 2D radiation patterns. Good agreement between measured and simulated outcomes is established. The results indicate that the proposed antenna, which performs well, may be appropriate for WLAN/WiMAX applications, including those involving portable electronics and emerging technologies.
We investigate the electronic and magnetic structures of two-dimensional transition metal tri-chalcogenide CrSiTe
3
and CrGeTe
3
materials by carrying out first-principles calculations. The ...single-layer CrSiTe
3
and CrGeTe
3
are found to be a ferromagnetic insulator, where the presence of the strong
dpσ
-hybridization of Cr
e
g
-Te
p
plays a crucial role for the ferromagnetic coupling between Cr ions. We observe that the bandgaps and the interlayer magnetic order vary notably depending on the magnitude of on-site Coulomb interaction
U
for Cr
d
electrons. The bandgaps are formed between the Cr
e
g
conduction bands and the Te
p
valence bands for both CrSiTe
3
and CrGeTe
3
in the majority-spin channel. The dominant Te
p
antibonding character in the valence bands just below the Fermi level is related to the decrease of the bandgap for the increase of
U
. We elucidate the energy band diagram, which may serve to understand the electronic and magnetic properties of the
ABX
3
-type transition metal tri-chalcogenides in general.
Anaerobic digestion (AD) is a well-established technology used for producing biogas or biomethane alongside the slurry used as biofertilizer. However, using a variety of wastes and residuals as ...substrate and mixed cultures in the bioreactor makes AD as one of the most complicated biochemical processes employing hydrolytic, acidogenic, hydrogen-producing, acetate-forming bacteria as well as acetoclastic and hydrogenoclastic methanogens. Hydrogen and volatile fatty acids (VFAs) including acetic, propionic, isobutyric, butyric, isovaleric, valeric and caproic acid and other carboxylic acids such as succinic and lactic acids are formed as intermediate products. As these acids are important precursors for various industries as mixed or purified chemicals, the AD process can be bioengineered to produce VFAs alongside hydrogen and therefore biogas plants can become biorefineries. The current review paper provides the theory and means to produce and accumulate VFAs and hydrogen, inhibit their conversion to methane and to extract them as the final products. The effects of pretreatment, pH, temperature, hydraulic retention time (HRT), organic loading rate (OLR), chemical methane inhibitions, and heat shocking of the inoculum on VFAs accumulation, hydrogen production, VFAs composition, and the microbial community were discussed. Furthermore, this paper highlights the possible techniques for recovery of VFAs from the fermentation media in order to minimize product inhibition as well as to supply the carboxylates for downstream procedures.
In this work, β-Ga
2
O
3
thin films were deposited by pulsed laser deposition (PLD) with changing oxygen pressure in the chamber. The
θ
–2
θ
scan x-ray diffraction (XRD) results reveal that the ...quality of the thin film obviously deteriorates when the oxygen pressure is greater than 0.1 Pa. Photoluminescence (PL) spectra measured at room temperature show that the major emission band can be separated into three Gaussian bands at about 370 nm (∼3.34 eV), 410 nm (∼3.03 eV), and 453 nm (∼2.74 eV), respectively. Using this analysis combined with x-ray photoelectron spectroscopy (XPS), we found that the three luminescence peaks originate from a self-trapped hole (STH) (between two OII-s sites), (
V
Ga
+
V
O
)
1−
and
V
G
a
2
-
(tetrahedral site), respectively. This work provides us a way to tune the emission of β-Ga
2
O
3
thin films.
A self-powered ITO/ZnO/InP heterojunction photodetector has been demonstrated with a 10-nm ZnO interfacial layer deposited by atomic layer deposition as a hole-blocking layer. The presence of a ...valence band offset between InP and ZnO enhances the photocurrent. The valence band offset between InP and ZnO creates a sufficient barrier for hole movement. Low surface recombination under 520-nm laser irradiation produced maximum photoresponsivity of 44.2 mAW
−1
with an illumination power of 1 µW at zero bias. The ZnO-passivated self-powered photodetector shows fast response and improved photo-detecting properties. Furthermore, the highly sensitive photodetectors are demonstrated to record the heart pulse wave by measuring relative changes in blood volume of the finger vessels.