A new monolithic approach for mid-IR focal plane arrays

Antimonide-based photodetectors have recently been grown on a GaAs substrate by molecular beam epitaxy (MBE) and reported to have comparable performance to the devices grown on more expensive InSb and GaSb substrates. We demonstrated that GaAs, in addition to providing a cost saving substrate for antimonide-based semiconductor growth, can be used as a functional material to fabricate transistors and realize addressing circuits for the heterogeneously grown photodetectors. Based on co-integration of a GaAs MESFET with an InSb photodiode, we recently reported the first demonstration of a switchable and mid-IR sensible photo-pixel on a GaAs substrate that is suitable for large-scale integration into a focal plane array. In this work we report on the fabrication steps that we had to develop to deliver the integrated photo-pixel. Various highly controllable etch processes, both wet and dry etch based, were established for distinct material layers. Moreover, in order to avoid thermally-induced damage to the InSb detectors, a low temperature annealed Ohmic contact was used, and the processing temperature never exceeded 180 °C. Furthermore, since there is a considerable etch step (> 6 μm) that metal must straddle in order to interconnect the fabricated devices, we developed an intermediate step using polyimide to provide a smoothing section between the lower MESFET and upper photodiode regions of the device. This heterogeneous technology creates great potential to realize a new type of monolithic focal plane array of addressable pixels for imaging in the medium wavelength infrared range without the need for flip-chip bonding to a CMOS readout chip

How willing/unwilling are luxury hotels' staff to be empowered? A case of East Malaysia

Empowerment is widely viewed as a dynamic concept to improve service quality and operational efficiency in the hospitality industry. The most effective approaches to empowering employees are not always clear. This paper contributes to the literature by seeking to understand the underlying factors that motivate and demotivate employees' willingness to become empowered. Qualitative data was collected through 22 semi-structured interviews with managers, supervisors and employees of four and five-star rated hotels in East Malaysia. In addition to the expected factors such as employees' acquired knowledge and psychological empowerment, employees' values and beliefs were also found to influence their willingness to become empowered. These findings are important in understanding employee perspectives of empowerment practices in operations contexts of East Malaysian luxury hotels

Density and Mobility Impact on MANET Routing Protocols in a Maritime Environment

Mobile Ad-Hoc Networks (MANETS) are multi hop wireless networks, where a packet hops through a number of intermediate nodes within coverage range of each other to reach the intended destination. The novel application of MANET routing protocols in the marine environment using available technology is one of the contributions of this work. The high cost of other available technologies which require direct connection to IP networks make our approach an attractive proposition for small craft. In this paper we investigate the effect of different maritime traffic patterns on the performance of three different MANET routing protocols which are Ad hoc On-Demand Distance Vector (AODV), Ad hoc On-Demand Multi Path Distance Vector (AOMDV) and Destination-Sequenced Distance Vector (DSDV). The traffic patterns are represented by different node densities and mobility behaviours which are likely to be found in the marine environment. Performance evaluation of the MANET protocols is compared in terms of packet delivery ratio

(AMDC) Algorithm for wireless sensor networks in the marine environment

Abstract—Data compression is known today as one of the most important enabling technologies that form the foundation of the majority of data applications and networks as we know them, including wireless sensor networks and the popular world wide net (internet). Marine data networks are gaining increasing interest in the research community due to the increasing request for data services over the sea. There are a very narrow range of available solutions because of the absence of infrastructure over such vast water surfaces. We have previously proposed applying MANET networks in the marine environment using VHF technology available on the majority of ships and vessels in order to gather different sensor data such as sea depth, temperature, wind speed and direction, etc. and send it to a central server to produce a public information map. We also discusses the gains and drawbacks of our proposal including the problem of low rate data transmission offered by VHF radio limited to 9.6 Kbps. In this paper we investigate the application of appropriate data quantization and compression techniques to the marine sensor data collected in order to reduce the burden on the channel links and achieve better transmission efficiency. Keywords—Wireless sensor network, Mobile Ad hoc Network, Very High Frequency, Sensor

Study of Some Physical and Chemical Properties of the Rock Samples Selected from Wells N 18 in the Field of Nasiriya and its Oil

This study was based on that hydrocarbon compounds originating in the oil can be leaked from the reservoir of and oil rising to the surface through the different layers. This study followed up relied change concentrations of these compounds and concentrations of elements associated with the change as a way to track it's path rises of such material in a Well 18 (Al- Nasiriya Field) through rock samples taken from various depths along the column of the Well trying to find some kind of comparison between the change 1 Qw2`\`W2\ of focus and depth of the Well.The quantitative and qualitative analyses have been conducted of trace metals in the organic extract from the rock samples using Atomic Absorption Spectroscopy and these elements are sodium, potassium, chromium and nickel. Samples were digested using a mixture of nitric acid concentration of 20% and 20% HCl concentration and by (2:1) volume ratio. The organic content extracted from rock samples contains a compound N- Ethyl Carbazole only, as is clear from the analysis of chromatographic (GC) of the samples. Carbazole rise to the top of the well's column. Some physical and chemical properties of crude oil such as: specific gravity, specific weight API, water content and salt content were measured. Through these properties were found that the oil is considered of medium quality oils and relatively close to the earth's surface and thus it can be extracted with little cost. Keywords: Crude Oil, Trace metals, Ethyl carbazol

ANTIPROLIFERATIVE AND ANTIOXIDANT ACTIVITY OF LEAVES EXTRACTS OF MORINGA OLEIFERA

Objective: The aim of the study was to investigate the ethanolic and aqueous extract of leaves of Moringa oleifera for phytochemical constituents, antiproliferative and antioxidant activity.Methods: The ethanolic extract of leaves of Moringa oleifera, belonging to the family Moringaceae was prepared by using soxhlet apparatus and aqueous extract was prepared by using maceration process. The extract was evaluated for its phytochemical constituents. The antiproliferative effects of both extracts were checked by using MTT ([3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide]) assay on HT-29 colon cell line and the antioxidant activity were checked by using DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. In antiproliferative and antioxidant activity the 5-FU (5-fluro uracil) and Ascorbic acid used as a standard drug for present results conclusion respectively.Results: The results obtained in MTT assay shown that ethanolic extract of Moringa oleifera had a more potent antiproliferative effect (growth inhibition of 62.25% at 100 μg/ml) on HT-29 colon cell line as compared to aqueous extract (% growth inhibition of 27.86 at 100 μg/ml) of Moringa oleifera. The ethanolic extract of Moringa oleifera shown more potent antioxidant activity (% inhibition of ethanolic 75.57 at 100 μg/ml) than aqueous extract (38.16 at 100 μg/ml) of Moringa oleifera. The activity shown by the extract is concentration dependent.Conclusion: In the present study we have investigated that the effect of ethanolic and aqueous leaves extracts of Moringa oleifera possess antiproliferative and antioxidant properties

Describing Polymers Synthesized from Reducing Sugars and Ammonia Employing FTIR Spectroscopy

          يمكن تشخيص الميلانويد باستخدام تقنية مطيافية الأشعة تحت الحمراء (FTIR) . أن UV/Vis هي أداة فعالة للتحليل النوعي والكمي للمكونات الكيميائية في بوليمرات الميلانودين. تتطابق الميزات الهيكلية والاهتزازية للميلانويدات المُصنَّعة من D-Glucose و D-Fructose ، وفقًا لأطياف FTIR ، مع الاختلاف الوحيد في شدة القمم. باستخدام أطياف FTIR ، ينقسم الهيكل التركيبي للميلانودين إلى سبع مناطق رئيسية. تم تأكيد وجود مجموعات C = C و C = N و C = O في جميع الميلانويدات المكونة من الفركتوز والجلوكوز مع الأمونيا من خلال المناطق التي تتراوح من 1600 إلى 1690 سم -1 ، ويتضح النطاق إلى حد كبير على أنه نطاق واسع. يحتوي كل من الميلانويدات على كربوكسيل أو كربونيل في المنطقة تقريبا 1700 سم -1. في جميع الميلانويدينات، اختفت مجموعة +NH في نطاق 3080 سم-1. ومع ذلك ، فإن كثافة اللون تعتمد على نوع السكر المستخدم في تخليق الميلانويدين. علاوة على ذلك، بالمقارنة مع ميلانويدين المخلق من الأمونيا و الكلوكوز Glc-ammoina ، التي تحتوي على نسبة أعلى من الكربون المهجن sp3 ، فإن الميلانويدين المخلق من الأمونيا و الفركتوز Fru-ammonia لديها نسبة أعلى من الكربون المهجن sp2 على أساس تحليل الأشعة فوق البنفسجية / المرئية و FTIR وأطياف المشتق الثاني. علاوة على ذلك ، تمت محاكاة البيانات بأستخدام تحليل المكون الرئيسي (PCA). تم استخدام تحليل المكون الرئيسي (PCA) لتفسير البيانات.          Melanoidins can be diagnosed using the Fourier transform infrared (FTIR) technique. UV/Vis is an effective tool for both qualitative and quantitative analysis of chemical components in melanoidin polymers. The structural and vibrational features of melanoidin synthesized from D-glucose and D-fructose are identical, according to FTIR spectra, with the only difference being the intensity of bands.  Using FTIR spectra, the skeleton of melanoidin is divided into seven major regions. The existence of the C=C, C=N, and C=O groups in all melanoidins formed from fructose and glucose with ammonia is confirmed by the areas ranging from 1600 to 1690 cm-1, and the band is largely evident as a broad shoulder. Both melanoidins have a carboxyl or carbonyl extending around 1700 cm-1. In all melanoidins, the NH+ group has vanished in the 3080 cm-1 range. However, the color intensity depends on the type of sugar employed in melanoidin synthesis. Furthermore, in comparison to Glc-ammonia, which has a higher proportion of sp3 hybridized carbon, Fru-ammonia has a higher proportion of sp2 hybridized carbon based on UV/Vis, FTIR and second-derivative spectra. Moreover, the data were simulated using principal component analysis. Principal component analysis (PCA) was used to interpret the data