3,839 research outputs found
Cryogenic pressure transducer
Cryogenic pressure transducer utilizes a diaphragm which is electron beam welded to a fitting. This assembly is then heliarc welded to the main body of the transducer. The transducer requires no damping oil and thus is capable of operating at both cryogenic and high temperatures
Instructional Staff Perceptions of Culturally Responsive Leadership
The rise of accountability standards has resulted in an increase of attention regarding the academic achievement of minority student populations. Instructional leadership styles that operate within frameworks that specifically address race and ethnicity have been shown to be positively correlated with academic outcomes of both majority and minority student populations. Culturally responsive leadership is one of these frameworks. While the literature offers a robust vision of the behaviors and subsequent results of culturally responsive leadership, we do not yet know the perceptions held by instructional staff regarding the culturally responsive leadership of their school leader. This lack of knowledge can not only hinder the ability of school leaders to respond appropriately in various situations, but it can also pose a threat to the perceived legitimacy of onesâ leadership. The purpose of this study was to understand the range of perceptions that instructional staff hold regarding the culturally responsive behaviors of their school leader. I conducted a qualitative single site case study focusing on the instructional staff of a school in the Midwest to learn what perceptions are held by instructional staff regarding the culturally responsive behaviors of their school leader.
In this study, I found that the perceptions participants had regarding the culturally responsive leadership of their school leader was not specific to the school leader (principal) but instead reflective of interactions held with a variety of individuals (principal. assistant principal, and instructional coach). I found that initial perceptions did change over time and could be contextualized through a conceptual change framework. I also found that the notion of safety played a part in determining if initial perceptions would change or not change. Though not in response to a specific research question, I did identify a repeated occurrence of goal displacement that was viewed across all three guiding research questions. This research provides a basis for exploring teacher perceptions of culturally responsive behaviors of their school principal and identified that there are still opportunities for further research within this topic
Improved Survival after Administration of Neoadjuvant Chemotherapy in Patients with Clinical Stage I/II Pancreatic Ductal Adenocarcinoma
Background: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of US cancer related deaths. This study assessed the oncologic benefit of a neoadjuvant chemotherapy (NAC) treatment strategy for patients with clinical Stage I/II PDAC.
Methods: Patients with biopsy confirmed PDAC and clinical Stage I/II disease were treated with a protocol of NAC. The primary study endpoint was median overall survival (OS). Kaplan-Meier survival curves were compared using the log-rank test.
Results: 56 patients met inclusion criteria. Of these, 21 patients (38%) had Stage I disease and 35 (62%) had Stage II disease. The median OS for the entire study population was 18.7 months. A total of 22 (39%) patients were managed with NAC+S; 34 (61%) received NAC alone. Median OS and 2-year survival rates were greater in those completing NAC+S compared to NAC alone (median OS 28.8 months vs. 17.3 months: p=0.05; 2-year OS: 55% vs 21%: p=0.01) . Interestingly, patients managed with NAC who were not candidates for surgical resection after restaging demonstrated a survival advantage (17.3 months) compared to what was previously reported in historical controls.
Conclusion: NAC+S provided a significant 11.5 month improvement in median OS compared to treatment with NAC alone. Modern NAC may contribute a significant oncologic benefit in the overall treatment strategy for patients with Stage I/II PDAC, even if surgery is not ultimately pursued
Directional solidification of flake and nodular cast iron during KC-135 low-g maneuvers
Alloys solidified in a low-gravity environment can, due to the elimination of sedimentation and convection, form unique and often desirable microstructures. One method of studying the effects of low-gravity (low-g) on alloy solidification was the use of the NASA KC-135 aircraft flying repetitive low-g maneuvers. Each maneuver gives from 20 to 30 seconds of low-g which is between about 0.1 and 0.001 gravity. A directional solidification furnace was used to study the behavior of off eutectic composition case irons in a low-g environment. The solidification interface of hypereutectic flake and spheroidal graphite case irons was slowly advanced through a rod sample, 5 mm in diameter. Controlled solidification was continued through a number of aircraft parabolas. The known solidification rate of the sample was then correlated with accelerometer data to determine the gravity level during solidification for any location of the sample. The thermal gradient and solidification rate were controlled independently. Samples run on the KC-135 aircraft exhibited bands of coarser graphite or of larger nodules usually corresponding to the regions solidified under low-g. Samples containing high phosphorous (used in order to determine the eutectic cell) exhibited larger eutectic cells in the low-g zone, followed by a band of coarser graphite
On a branch-and-bound approach for a Huff-like Stackelberg location problem
Modelling the location decision of two competing firms that intend to build a new facility in a planar market can be done by a Huff-like Stackelberg location problem. In a Huff-like model, the market share captured by a firm is given by a gravity model determined by distance calculations to facilities. In a Stackelberg model, the leader is the firm that locates first and takes into account the actions of the competing chain (follower) locating a new facility after the leader. The follower problem is known to be a hard global optimisation problem. The leader problem is even harder, since the leader has to decide on location given the optimal action of the follower. So far, in literature only heuristic approaches have been tested to solve the leader problem. Our research question is to solve the leader problem rigorously in the sense of having a guarantee on the reached accuracy. To answer this question, we develop a branch-and-bound approach. Essentially, the bounding is based on the zero sum concept: what is gain for one chain is loss for the other. We also discuss several ways of creating bounds for the underlying (follower) sub-problems, and show their performance for numerical cases
Preliminary science report on the directional solidification of hypereutectic cast iron during KC-135 low-G maneuvers
An ADSS-P directional solidification furnace was reconfigured for operation on the KC-135 low-g aircraft. The system offers many advantages over quench ingot methods for study of the effects of sedimentation and convection on alloy formation. The directional sodification furnace system was first flown during the September 1982 series of flights. The microstructure of the hypereutectic cast iron sample solidified on one of these flights suggests a low-g effect on graphite morphology. Further experiments are needed to ascertain that this effect is due to low-gravity and to deduce which of the possible mechanisms is responsible for it
Studies on the Inheritance of Stemphylium Resistance in Tomatoes
Gray leaf spot of tomatoes, caused by Stemphylium solani Weber, is widespread and highly destructive in Hawaii. Control by application of fungicides is expensive and, in many instances, only partially successful. All the locally adapted, commercial varieties are susceptible. In a program to develop gray leaf spot resistant commercial varieties, tiny-fruited, resistant tomato lines (Lycopersicon pimpinellifolium and Targinnie Red - L. esculentum) were introduced. These were crossed with locally adapted susceptible varieties. Seed from such crosses was further propagated and back crossed to the two parents. First, second, and third generation seedlings, as well as backcross generations, were examined in greenhouse tests to determine the mode of inheritance of resistance. The data obtained indicate that resistance is governed by a single dominant genetic factor pair. This factor pair is assigned the symbol "Sm-sm.
Pola Pemanfaatan Ruang Bersama pada Rusunawa Jatinegara Barat
Relokasi warga Kampung Pulo ke Rusunawa Jatinegara Barat membuat warga harus beradaptasi dengan lingkungannya, khususnya dalam kegiatan interaksi sosial. Hal ini yang mendasari peneliti untuk melakukan pengamatan mengenai pola pemanfaatan ruang bersama untuk kegiatan interaksi sosial, baik ruang bersama yang direncanakan maupun ruang bersama yang tidak direncanakan. Tujuan dari penelitian ini untuk menilai keberhasilan adaptasi penghuni dalam memenuhi kebutuhannya dalam berinteraksi dan mengetahui faktor yang mempengaruhi pola ruang bersama. Metode pengumpulan data menggunakan âmapping behaviorâ, yaitu cara untuk menggambarkan perilaku dalam peta, mengidentifikasikan jenis frekuensi perilaku, serta menunjukkan kaitan perilaku dengan wujud perancangan yang spesifik. Karena pola ruang tercipta akibat hubungan timbal Balik antara manusia dengan ruang.Penelitian ini menggunakan teknik analisis deskriptif kualitatif, yaitu menerjemahkan data hasil observasi dan data hasil wawancara ke dalam bentuk uraian yang dapat lebih dimengerti. Penghuni memanfaatkan ruang bersama yang direncanakan dan tidak direncanakan untuk berinteraksi sosial antar penghuni. Pemanfaatan ruang telah menghasilkan sebuah pola-pola ruang bersama yaitu pola dengan intensitas tinggi dan pola dengan intensitas rendah. Ruang bersama dengan intensitas penggunaan tinggi relatif jauh dari hunian dengan frekuensi penggunaan jam-harian. Adapun ruang yang digunakan yaitu selasar lantai hunian, plaza terbuka, area pujasera, taman bermain dan lobby lift
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