bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Observations of Hypoxia off the Yangtze River Estuary: Toward Prediction and Operational Application
Authors:   Second Institute of Oceanography, Ni Xiaobo , Zhou Feng , Zeng Dingyong , Li Dewang , Zhang Tao , Wang Kui , Ma Yunlong , Meng Qicheng , Ma Xiao , Zhang Qianjiang , Huang Daji , Chen Jianfang
Published: January 2023

Dissolved oxygen (DO) is essential for the survival of most aquatic organisms. Hypoxia, defined as a DO concentration of less than 2 mg L–1, is a significant issue for ecosystems in estuaries and coastal waters and is one of the top themes of the United Nations Decade of Ocean Science for Sustainable Development (2021–2030). An area off the Yangtze River Estuary (YRE), China, annually develops one of the world ocean’s largest hypoxic areas. Observations collected by ship since 1999, and by long-term sensors since 2009, show that DO concentration in this region has been both declining and greatly fluctuating.
The stabilization effect of peat soil using an effective microorganism reviewed from CBR Value
Authors:   Master Students of Engineering Civil, Faculty of Engineering, Universitas Lambung Mangkurat, Jl. Brigjend Hasan Basri, Pangeran, Banjarmasin, South Kalimantan, 70123, Indonesia, RAMADHANI MUHAMMAD RIZQI , RUSDIANSYAH  ,   Master Lecturer of Engineering Civil, Faculty of Engineering, Universitas Lambung Mangkurat, Jl. Brigjend Hasan Basri, Pangeran, Banjarmasin, South Kalimantan, 70123, Indonesia
Published: January 2023

The behavior of peat soil's physical characteristics and the mechanism are extremely influenced by the decomposition degree. This study aims to know a physique range alteration and mechanism of the peat soil fibrous reviewed from the enhanced value of California Bearing Ratio (CBR) after it is stabilized using Effective Microorganism (EM). The volume of EM inserted and combined are 20% and 40% that ripened for 14 and 21 days. Then the peat soil and EM are mixed with water content close to original peat soil volume. The results showed that the most significant change in peat soil's physical characteristics and the mechanism is 40% EM solution with maximum decomposition rate occurs at the 14-days ripening period. The fiber content is reduced from 60% to 52%, and decomposition rate 0% fiber/day to 0.57% fiber/day, and the increased value of unsoaked CBR 3.28% to 7.47% and 3.01% to 6.11% in wet conditions.
Using CoMIFs in structural modal testing
Authors:   Politehnica University of Bucharest, Splaiul Independenţei 313, Bucharest, Romania, RADEŞ MIRCEA
Published: January 2023

This paper reports experience in using two Componentwise Mode Indicator Functions to locate the modes of vibration of a real structure with sufficiently separated frequencies. The advantages of using selected sets of measurement points and different limited frequency bands are emphasized.
Science & Humanities Vol. 1 Nº 1 2017
Authors: Arpasi Chura Rodolfo Fredy
Published: January 2023

La Universidad Andina Néstor Cáceres Velásquez (UANCV) desde su fundación, el 23 de octubre de 1981, Ley Nº 23738, se ha comprometido con la formación superior y la investigación científica en la región sur del Perú a nivel de grado y posgrado, del mismo modo, mediante Resolución Nº 0655–2000–ANR, la ex Asamblea Nacional de Rectores (ANR) autorizó el funcionamiento de la Escuela de Posgrado.
COCIENTE TRICEREBRAL EN EL APEGO FAMILIAR EN PROFESIONALES DE MAESTRÍA DE LA UNIVERSIDAD ANDINA NÉSTOR CÁCERES VELÁSQUEZ
Authors: Fernández M. Sandra , Aguilar V. Roxana , Johnson A. Grover
Published: January 2023

Las actividades motoras, intelectuales y emocionales del cerebro, influyen de forma positiva o negativa hacia la construcción y el apego familiar, esto estará vinculado durante todo el ciclo de vida a la persona y a sus futuras generaciones. Los objetivos de la investigación fueron: analizar el cociente tricerebral, identificar el dominio cerebral, establecer la escala de intensidad horizontal, la proporcionalidad, el subgrupo dominante, y su influencia en el apego familiar de profesionales de maestría en salud pública. En la metodología se empleó el enfoque cuantitativo, tipo explicativo, tomando como muestra a 43 profesionales de la salud del I semestre de Maestría en Salud Pública, se utilizaron como instrumentos: el revelador del cociente tríadico, para diagnosticar las manifestaciones del cerebro triádico, diseñado y validado por De Gregory y el sociograma como técnica de sociometría diseñada para evaluar relaciones interpersonales en este caso familiares. En los resultados encontramos 44,2 % de dominio cerebral derecho, 55,8 % en escala de intensidad superior, 48,8 % tuvieron proporcionalidad, el satisfactor dominante fue en 39,5 % el oficial- dominante y el sexo femenino con 65,1 % tiene mayor apego a los padres; concluyendo que existe influencia significativa entre el cociente tricerebral y el apego familiar a favor de los padres, seguida de la pareja y los hermanos; estos hallazgos constituyen fuente relevante de información para adoptar conductas proactivas en la sociedad, desde la educación del cerebro triuno para vivir en una sociedad más proporcional.
Svět pro děti do tří let
Authors: Grůzová Lucie , Jarkovská Lucie , Kampichler Martina , Slezáková Katarína
Published: January 2023

The book “A World for Children Under Three. Insights Into the Current Form of ECEC in the CR“ is the first pedagogical-sociological book in the CR dealing with current facilities for children under three years of age – children’s groups / micro-creches, kindergarten classes for two-year-olds, and children’s centres. It is addressed to professionals, students, parents and everyone else interested in bringing the worlds of parents, caregivers and children who meet in these facilities closer together. It presents key research findings of the project ECEC in Day Care Facilities in the CR, relating to children’s collective everyday life, the work of (head) teachers and nannies, and the experiences and expectations of parents, and relates them to the current system framework.
Allowing Surgical Pathology Fellows to Release Preliminary Reports Increases Learner Independence and Satisfaction
Authors: Boland Jennifer M. , Solanki Malvika H. , Fritchie Karen J. , Russell Teresa E. , Moen Benjamin P. , Graham Rondell P. , Maleszewski Joseph J. , Hernandez Loren P. Herrera
Published: January 2023

Context.—

Progressive independence in medicine is critical to building confidence and decisiveness in trainees. However, this can be difficult to accomplish in the strict regulatory environment of pathology.

Objective.—

To pilot and adopt a process whereby surgical pathology fellows independently manage a subset of cases and release preliminary reports.

Design.—

Upon program approval, board-certified surgical pathology fellows were eligible for preliminary report sign-out at their discretion. Eligible cases were sent from outside institutions for confirmatory review. Preliminary reports were viewable in the electronic medical record. Safety measures were used to ensure timely release of final reports by attending pathologists.

Results.—

Fellows participating in the pilot (n = 4) released 59 preliminary reports out of 101 cases reviewed (58%), with 1 potentially significant discrepancy between preliminary and final report. Turnaround time was not affected. The process was endorsed by all participants and adopted as standard practice. During the first year, eligible fellows (n = 8) released 123 preliminary reports out of 1260 cases reviewed (9.8%). There were no major diagnostic discrepancies and no effects on turnaround time. The number of preliminary reports released by each fellow was variable (range, 2–48; median, 8), likely a reflection of both external factors (number of trainees on service, volume) and trainee-specific factors (confidence, efficiency).

Conclusions.—

Fellows showed good judgment when independently managing cases, with just 1 potentially significant discrepancy out of 182 cases (<1%). No patients were adversely impacted. Use of this process varied widely among fellows and may require closer monitoring and encouragement for fellows who are tentative about releasing preliminary reports.
Social Work in Suits: A Case Study on the Corporate Social Responsibility (CSR) Initiatives of Widus Foundation, Inc. (WFI)
Authors: Paola Ellaine D.Luzon  , Jennifer Mae I.Milan  , Eunice M.Noveno
Published: January 2023

The interconnectedness of corporate social responsibility (CSR) and social work has been established in past studies. However, there is still a lack of participation of social workers in the CSR field. This study aimed to describe and analyze the CSR initiatives of Widus Foundation, Inc. (WFI), a CSR company in the Philippines whose foundation manager is a social worker. A case study was done on the CSR program delivery of the WFI by collecting data through an online interview and questionnaire with the WFI foundation manager. Thematic analysis was used to analyze online interviews with WFI volunteers and beneficiaries to determine CSR best practices of the WFI. Findings showed that the CSR framework used by the WFI focuses on being inclusive, impact-driven, sustainable, and innovative or unique. Moreover, CSR best practices of the WFI that emerged from interviews with stakeholders were: (1) inclusive, (2) sustainable, (3) impactful, and (4) good administration. Results of this study can be used to establish the importance of social workers in the CSR field. The best practices identified can also serve as a starting point to establish standards in CSR delivery. Future studies may also be done on a wider scale involving several CSR companies.
Inclusive Finance in Sembako Program: An Overview From Proper Governance Perspective
Authors: Habibullah  , Jayaputra Achmadi , Pudjianto Bambang , Muhtar
Published: January 2023

The Sembako program is one of the social protection programs launched by the Government of Indonesia to overcome poverty by providing food assistance. The sembako program is also expected to increase financial inclusion by using the prosperous family card as an electronic money and savings feature. This study uses a proper governance perspective with the research location in Banyumas Regency, Central Java Province, Indonesia. The results showed that the implementation of the Sembako program went well. However, the recipients complain that  the types, quantities, and goods received are different from the instructed provisions, so they are not in accordance with the principles of proper governance. The sembako program contributes little to increasing financial inclusion because the KKS Card can only be used to take assistance from the sembako program and cannot access other banking services. It was found that the KKS Card was not held by the recipient of the basic food program, and the recipient did not memorize the KKS Card Pin. This study recommends that all shops and stalls carry out the distribution of the sembako program without being limited to certain stalls. The sembako program is not packaged so that beneficiaries are free to take basic food assistance according to the needs of their families.
Bazı Yaygın İnsektisitlerin Domates (L. esculentum Mill.) Bitkisinde Lipid Peroksidasyon ve Antioksidatif Sistem Üzerine Etkileri
Authors: YAKAR Sümeyra , TUNA Atilla Levent
Published: January 2023

Günümüzde entansif tarımda pestisit kullanımı yüksek düzeylerdedir. Bu kimyasalların bitkilerde morfolojik, fizyolojik ve biyokimyasal değişikliklere neden oldukları da gösterilmiştir. Muğla İli ülkemizde yoğun bir sera potansiyeline sahiptir ve pestisit kullanımı da üst düzeydedir. Bu çalışmada, Imidacloprid, Abamectin ve Acetamiprid etken maddeli insektisitlerin sera domatesi bitkisinde potansiyel oksidatif stres izlerini araştırmak ve lipit peroksidasyon düzeyi ile antioksidatif sistemin uyarılma derecesini ortaya koymak yoluyla bitkinin strese yanıtını belirlemek amaçlanmıştır. İnsektisit uygulamalarına bağlı olarak, prolin, klorofil ve malondialdehit (MDA) ile oksidatif stres durumunda bitkinin antioksidatif yanıtını belirlemek amacıyla süperoksit dismutaz (SOD), peroksidaz (POX) ve katalaz (CAT) spesifik enzim aktiviteleri belirlenmiştir. Bulgularımıza göre Imidacloprid insektisiti, kontrole göre MDA ve prolin kasamlarını arttırmış ancak antioksidatif sistemi uyararak kontrole göre 200 ve 400 µl/L dozlarında POX ve SOD enzim aktivitelerini yükseltmiştir. Abamectin insektisiti MDA kapsamını kontrole göre tüm dozlarda, prolin kapsamını ise ilk 2 dozda arttırmış, buna karşın antioksidatif sistem uyarılarak tüm enzim aktivitelerinde artış kaydedilmiştir. Acetamiprid insektisiti ise özellikle 0.3 g/L konsantrasyonda prolin kapsamını aşırı derecede uyararak lipid peroksidasyon düzeyinin baskılanmasına sebebiyet vermiştir. Elde edilen veriler, her 3 insektisitin de domates bitkisinde prolin ve lipit peroksidasyonu arttırarak antioksidatif sistemin uyarılmasına neden olduğunu göstermektedir.
Man in Ash‘arite Theology : Examining Muhammad Sa‘id Ramadan Al-Bouti’s Contemporary Interpretation of Al-Ash‘ari’s Kalam in His “The Greatest Cosmic Certainties”
Authors:   Ez-Zitouna University, The Higher Institute of Islamic Civilisation in Tunis, Abdellatif Yahia
Published: January 2023

Within the framework of seeking the renewal of the Ash‘arite Kalām (theology) and the context of understanding the human tendency to believe and establish faith, this paper aims at studying the presence of man within the contemporary Ash‘arite theology. It focuses on one of its most prominent contemporary pioneers, Muhammad Sa‘id Ramadan Al-Bouti, through his most renowned book in the field of faith, “The Greatest Cosmic Certainties”. This paper has sought to track the theme of man across the entire book, while analyzing and criticizing the way Al-Bouti dealt with this concept and focusing on Al-Bouti’s special interest to develop our understanding of man within the Ash‘arite Sunni theology.
Penalty for Late Payment: The Study of Shariah Risk in Islamic Housing Products in Malaysia
Authors:   Faculty of Islamic Studies, Kolej Universiti Islam Perlis, Malaysia, Muhamad Asni Muhammad Fathullah Al Haq , Ishak Muhammad Shahrul Ifwat ,   Faculty of Business and Management, Universiti Sultan Zainal Abidin (UniSZA), Malaysia, Fatah Yasin Mohammad Dhiya'ul Hafidh ,   Faculty of Islamic Studies, Kolej Universiti Islam Perlis, Malaysia
Published: January 2023

The Islamic banking scheme has become an alternative to the conventional banking scheme since conventional banking is based on riba, that strongly prohibited by Shariah. Islamic banking scheme charges profit through Islamic-authorised sale and leasing transactions between banks and customers. However, through the sale and leasing transactions entered into, the customer is also required to purchase and rent in instalments as specified in the contract. If the client is late paying the specified instalment, how does the bank engage with it? Hence, the study to identify the management of Shariah risk by selected banks through the practice of Islamic housing financing contracts in dealing with the issue of customer default. This study was conducted qualitatively using two main methods: library research and the unstructured interview method. The library research method is applied to build the research theory by reviewing related literature and official websites. As for the interview, it is conducted to obtain primary data on the practice of late payment fines namely ta’wid (compensation) and gharamah (penalty) in selected banks. The researchers apply a purposive sampling method in conducting the interview technique by interviewing experienced and knowledgeable respondents regarding the issue. As a result, this study found that out of the six banks surveyed, only two banks impose two both ta’wid and gharamah, while the other four banks prefer ta’wid fines. The study also found that the Shariah risk solution to the practice of charges imposed by banks is based on the stipulation set by Bank Negara Malaysia (BNM). This can be learned that only the government can fine offenders through the concept of ta’zir and BNM has delegated its power to the bank to carry out the charge to defaulting customers.
Modelling of Arabic Plosive and Fricative Acoustic Characteristics Articulated by Malay Native Speakers
Authors:   Pusat Pengajian Bahasa Arab, Fakulti Bahasa dan Komunikasi Universiti Sultan Zainal Abidin, Terengganu, Malaysia, Paharal Radzi Majdan , A. Hamid Shahidi ,   Pusat Kajian Bahasa, Fakulti Sains Sosial dan Kemanusiaan Universiti Kebangsaan Malaysia, Malaysia
Published: January 2023

This study aims to examine the pharyngealized and non-pharyngealized Arabic sounds produced by Malay speakers based on acoustic phonetic approach and to investigate its relation with the second language learning model proposed by Flege (1995). The plosive and fricative associated with the pharyngealized and non-pharyngealized of Arabic sounds is one of the main problems among non-Arabic native speakers in learning Arabic language. Recent studies emphasize the influence of the first language / mother tongue language as the cause of the failure to master the Arabic language as the second language. Hence the frameworks of the similar, different and new sound hypotheses proposed by Flege (1995) were used to get the real picture of the Arabic language speech phenomenon in the second language condition. PRAAT software was used to obtain speech data in the spectrogram and to undergo spectrograph analysis. Subsequently, the findings were analyzed using SPSS to highlight the overall results of the study more thoroughly. VOT (Voice Onset Time) acoustic parameters for the plosive sound and frication of the frication sounds were used during the spectrograph analysis. A total of 2880 spectrogram data were obtained from the subjects: 24 undergraduates from the Bachelor of Islamic Studies with Honors (Arabic Studies and Islamic Civilization) UKM. The results of the production experiment show that Malay plosive sound has negative VOT for voiced stop and short positive VOT for voiceless stop, while Arabic plosive sounds has a model pattern voicing lead versus long lag for voiced and voiceless stops respectively. The results show that Arabic voiceless stop / ت / is aspirated and found to has a longer VOT than Malay voiceless stop /t/. For Arabic pharyngealized sounds, the results show higher values of F1 than non-pharyngealized sounds. In addition, Arabic pharyngealized sounds are found to have shorter VOT than non-pharyngealized Arabic sounds. The findings showed that there were cases where subjects managed to replicate the L2 sound to similar sound of L1 and there were cases of L2 sounds that are foreign to the sound system of L1. With that in mind, it can be emphasized that some studies have supported Flege’s theory that the similar sound between L1 and L2 are not necessarily easy to pronounce, while there are L2 phonemes that are absent in L1, but they are easily learnt by the L2 speaker.
Temporal derivative computation in the dorsal raphe network revealed by an experimentally driven augmented integrate-and-fire modeling framework
Authors: Harkin Emerson F , Lynn Michael B , Payeur Alexandre , Boucher Jean-François , Caya-Bissonnette Léa , Cyr Dominic , Stewart Chloe , Longtin André , Naud Richard , Béïque Jean-Claude
Published: January 2023

By means of an expansive innervation, the serotonin (5-HT) neurons of the dorsal raphe nucleus (DRN) are positioned to enact coordinated modulation of circuits distributed across the entire brain in order to adaptively regulate behavior. Yet the network computations that emerge from the excitability and connectivity features of the DRN are still poorly understood. To gain insight into these computations, we began by carrying out a detailed electrophysiological characterization of genetically identified mouse 5-HT and somatostatin (SOM) neurons. We next developed a single-neuron modeling framework that combines the realism of Hodgkin-Huxley models with the simplicity and predictive power of generalized integrate-and-fire models. We found that feedforward inhibition of 5-HT neurons by heterogeneous SOM neurons implemented divisive inhibition, while endocannabinoid-mediated modulation of excitatory drive to the DRN increased the gain of 5-HT output. Our most striking finding was that the output of the DRN encodes a mixture of the intensity and temporal derivative of its input, and that the temporal derivative component dominates this mixture precisely when the input is increasing rapidly. This network computation primarily emerged from prominent adaptation mechanisms found in 5-HT neurons, including a previously undescribed dynamic threshold. By applying a bottom-up neural network modeling approach, our results suggest that the DRN is particularly apt to encode input changes over short timescales, reflecting one of the salient emerging computations that dominate its output to regulate behavior.
T follicular helper 17 (Tfh17) cells are superior for immunological memory maintenance
Authors: Gao Xin , Luo Kaiming , Wang Diya , Wei Yunbo , Yao Yin , Deng Jun , Yang Yang , Zeng Qunxiong , Dong Xiaoru , Xiong Le , Gong Dongcheng , Lin Lin , Pohl Kai , Liu Shaoling , Liu Yu , Liu Lu , Nguyen Thi HO , Allen Lilith F , Kedzierska Katherine , Jin Yanliang , Du Mei-Rong , Chen Wanping , Lu Liangjing , Shen Nan , Liu Zheng , Cockburn Ian A , Luo Wenjing , Yu Di
Published: January 2023

A defining feature of successful vaccination is the ability to induce long-lived antigen-specific memory cells. T follicular helper (Tfh) cells specialize in providing help to B cells in mounting protective humoral immunity in infection and after vaccination. Memory Tfh cells that retain the CXCR5 expression can confer protection through enhancing humoral response upon antigen re-exposure but how they are maintained is poorly understood. CXCR5+ memory Tfh cells in human blood are divided into Tfh1, Tfh2, and Tfh17 cells by the expression of chemokine receptors CXCR3 and CCR6 associated with Th1 and Th17, respectively. Here, we developed a new method to induce Tfh1, Tfh2, and Tfh17-like (iTfh1, iTfh2, and iTfh17) mouse cells in vitro. Although all three iTfh subsets efficiently support antibody responses in recipient mice with immediate immunization, iTfh17 cells are superior to iTfh1 and iTfh2 cells in supporting antibody response to a later immunization after extended resting in vivo to mimic memory maintenance. Notably, the counterpart human Tfh17 cells are selectively enriched in CCR7+ central memory Tfh cells with survival and proliferative advantages. Furthermore, the analysis of multiple human cohorts that received different vaccines for HBV, influenza virus, tetanus toxin or measles revealed that vaccine-specific Tfh17 cells outcompete Tfh1 or Tfh2 cells for the persistence in memory phase. Therefore, the complementary mouse and human results showing the advantage of Tfh17 cells in maintenance and memory function supports the notion that Tfh17-induced immunization might be preferable in vaccine development to confer long-term protection.
Future COVID19 surges prediction based on SARS-CoV-2 mutations surveillance
Authors: Najar Fares Z , Linde Evan , Murphy Chelsea L , Borin Veniamin A , Wang Huan , Haider Shozeb , Agarwal Pratul K
Published: January 2023

COVID19 has aptly revealed that airborne viruses such as SARS-CoV-2 with the ability to rapidly mutate combined with high rates of transmission and fatality can cause a deadly worldwide pandemic in a matter of weeks (Plato et al., 2021). Apart from vaccines and post-infection treatment options, strategies for preparedness will be vital in responding to the current and future pandemics. Therefore, there is wide interest in approaches that allow predictions of increase in infections (‘surges’) before they occur. We describe here real-time genomic surveillance particularly based on mutation analysis, of viral proteins as a methodology for a priori determination of surge in number of infection cases. The full results are available for SARS-CoV-2 at http://pandemics.okstate.edu/covid19/, and are updated daily as new virus sequences become available. This approach is generic and will also be applicable to other pathogens.
Bone circuitry and interorgan skeletal crosstalk
Authors: Zaidi Mone , Kim Se-Min , Mathew Mehr , Korkmaz Funda , Sultana Farhath , Miyashita Sari , Gumerova Anisa Azatovna , Frolinger Tal , Moldavski Ofer , Barak Orly , Pallapati Anusha , Rojekar Satish , Caminis John , Ginzburg Yelena , Ryu Vitaly , Davies Terry F , Lizneva Daria , Rosen Clifford J , Yuen Tony
Published: January 2023

The past decade has seen significant advances in our understanding of skeletal homeostasis and the mechanisms that mediate the loss of bone integrity in disease. Recent breakthroughs have arisen mainly from identifying disease-causing mutations and modeling human bone disease in rodents, in essence, highlighting the integrative nature of skeletal physiology. It has become increasingly clear that bone cells, osteoblasts, osteoclasts, and osteocytes, communicate and regulate the fate of each other through RANK/RANKL/OPG, liver X receptors (LXRs), EphirinB2-EphB4 signaling, sphingolipids, and other membrane-associated proteins, such as semaphorins. Mounting evidence also showed that critical developmental pathways, namely, bone morphogenetic protein (BMP), NOTCH, and WNT, interact each other and play an important role in postnatal bone remodeling. The skeleton communicates not only with closely situated organs, such as bone marrow, muscle, and fat, but also with remote vital organs, such as the kidney, liver, and brain. The metabolic effect of bone-derived osteocalcin highlights a possible role of skeleton in energy homeostasis. Furthermore, studies using genetically modified rodent models disrupting the reciprocal relationship with tropic pituitary hormone and effector hormone have unraveled an independent role of pituitary hormone in skeletal remodeling beyond the role of regulating target endocrine glands. The cytokine-mediated skeletal actions and the evidence of local production of certain pituitary hormones by bone marrow-derived cells displays a unique endocrine-immune-skeletal connection. Here, we discuss recently elucidated mechanisms controlling the remodeling of bone, communication of bone cells with cells of other lineages, crosstalk between bone and vital organs, as well as opportunities for treating diseases of the skeleton.
Diffusion of implanted beryllium in n- and p-type GaAs
Authors: Deal Michael D. , Robinson Heyward G.
Published: July 2002

The diffusion of ion-implanted Be in GaAs is studied by comparing the diffusion of implanted Be in undoped GaAs and in GaAs uniformly doped with Zn or Si. The Si-doped sample exhibits much less Be diffusion compared to the undoped case, while the Zn-doped sample shows much more Be diffusion. The diffusion in the doped substrate cases can be simulated with a constant Be diffusivity, as opposed to a concentration-dependent diffusivity in the undoped case. The results are consistent with the substitutional-interstitial diffusion mechanism, which predicts a diffusivity that is dependent on the net hole concentration.
Novel drilling technique in polyimide using visible laser
Authors: Haba Belgacem , Morishige Yukio
Published: July 2002

We report a new and fast laser-drilling technique in polyimide. This drilling process consists of two steps. First, the polyimide is irradiated with millisecond pulse of visible laser light. Second, the debris inside and around the holes are ultrasonically cleaned in water in a short time. In this report, we also analyze the emitted light originated from the laser induced polyimide decomposition that leads to the drilling. The mechanism behind the drilling is believed to be associated to a volcano-eruption-like behavior. This inexpensive technique provides good quality drilling, high throughput, and very promising applications in packaging technology.
An apparatus for measuring angular dispersion of liquid drop streams
Authors: Qian Shao-Sheng , Guo Luwei , Yu Huizhong
Published: July 2002

A new method to measure angular dispersion of liquid drop streams with several optical fiber probes has been developed. Measurements for the number of drops at a variety of direction angles were done at a consecutive period.
An improved CARS spectrometer for single-shot measurements in turbulent combustion
Authors: Snelling D. R. , Sawchuk R. A. , Smallwood G. J. , Parameswaran T.
Published: July 2002

A broadband coherent anti-Stokes Raman spectroscopy (CARS) system optimized for single shot measurements in turbulent flames is described. The CARS spectrometer incorporates an intensified photodiode array (IPDA) with a P46-phosphor based intensifier that is shown to have an order of magnitude less image persistence than P20-phosphor based IPDAs, and thus largely eliminates the temperature errors that can result from this image persistence. The low and high signal nonlinearity of IPDAs incorporating both P20 and P46 phosphor based intensifiers is described. The CARS signal is dispersed with a single element concave holographic diffraction grating, which is fiber-optically coupled. To provide the necessary dynamic range (approximately 1000:1) to handle CARS spectra whose temperatures can vary from 300 K to adiabatic flame temperatures a fiber-optic splitter was employed and the nonlinearity of the IPDA detectors was characterized. A method of determining the nonlinearity was developed that was convenient and the fiber-optic link was shown to provide a stable calibration of this nonlinearity. The problem of dye laser spectral drift, which is particularly severe in a long duration experiment, was addressed by constructing a compact high resolution spectrometer to continuously monitor the dye laser. The dye laser center frequency was maintained constant by manually adjusting an intracavity tuning filter. The accuracy of this technique and its effect on CARS derived temperatures was evaluated. The standard method of determining the instrument function by fitting to 295 K air spectra was compared to other methods and its use was shown to result in an uncertainty of less than 0.5% in CARS derived temperatures. The operation of this CARS instrument was demonstrated in a turbulent diffusion flame. The varying composition in these flames was accounted for by fitting C, the ratio of the nitrogen mole fraction to the total third order nonlinear susceptibility.
Conversion of a double crystal diffractometer to a high resolution triple crystal diffractometer
Authors: Matyi R. J.
Published: July 2002

The conversion of a commercial double crystal x-ray diffractometer to a flexible, high-resolution triple crystal diffractometer is described. This conversion, which has been accomplished at low cost, greatly enhances the flexibility of a double crystal diffractometer for the characterization of both highly perfect and relatively imperfect bulk single crystals and epitaxial layers. The conversion is easily reversible, thus allowing a single double crystal diffractometer to operate in either a double crystal or triple crystal mode. Specific examples of the capabilities of this instrument are presented.
Adaption of synchronously scanned luminescence spectroscopy to organic-rich fluid inclusion microanalysis
Authors: Musgrave John A. , Carey Russell G. , Janecky David R. , Tait C. Drew
Published: July 2002

The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectroscopy technique described here can be used to classify microliter quantities of oil such as those in fluid inclusions in cements from petroleum reservoirs. It is primarily constructed to obtain synchronously scanned luminescence spectra from microscopic sized samples to characterize the organic classes of compounds that predominate. At present no other technique can so readily analyze a single oil-bearing fluid inclusion. The data collected from the technique are pertinent to evaluating systems and providing quantitative data for solving problems in oil migration and maturation determinations, oil-to-oil and oil-to-source correlations, oil degradation, and episodes and chemistry of cementation.
RELAX: An ultrasensitive, resonance ionization mass spectrometer for xenon
Authors: Gilmour J. D. , Lyon I. C. , Johnston W. A. , Turner G.
Published: July 2002

RELAX is a resonance ionization, time-of-flight mass spectrometer to which a cryogenic sample concentrator has been added. This has resulted in an increase in sensitivity by a factor greater than 100. The sample concentrator consists of a localized cold spot in the ion source, onto which the sample condenses, and a heating laser to release the condensed sample into the ionization region. The lifetime against detection of a sample atom is close to 20 min, which corresponds to a count rate of 1 cps from a sample of 1000 atoms, while the mass resolution is 300 (10% peak height). Sensitivity depends on the return time of sample atoms to the cold spot (10 s) and the fraction of these atoms subsequently ionized (∼1%). The minimum sample size which can be measured is limited only by blank, which is currently 2×10−15 cc STP total xenon and isotopically atmospheric (this can be attributed to the large aliquots of xenon admitted to the instrument during development, and so may be expected to decrease with time). The precision of abundance measurements has been improved by the incorporation of pulse height discrimination and pulse counting detection for the less abundant isotopes. The design, construction, and operation of the spectrometer in its new configuration are described with particular attention to abundance extraction. The effects of the sample concentrator on ionization efficiency and discrimination are discussed in detail, as are interferences from nonresonantly ionized hydrocarbons and the means of accounting for them.
A high-pressure cell for optical microscopy and measurements on the phase diagram of poly(diethylsiloxane)
Authors: Reck T. , Sautter E. , Dollhopf W. , Pechhold W.
Published: July 2002

A new high-pressure cell as useful equipment for a polarizing microscope is described. Measurements in a temperature range between −40 and +270 °C under hydrostatic pressures up to 300 MPa allow for example the observation of polymer morphology and phase transitions. In addition to a documentation on video and photograph, respectively, the computer-controlled light intensity measurement offers the possibility of a quantitative analysis. Investigations on the phase diagram of poly(diethylsiloxane) have been carried out and show, that the transition temperature from mesophase to isotropic melt decreases with increasing pressure for pressures above 160 MPa.
Polarized light emission from a calamitic liquid crystalline semiconductor doped with dyes
Authors: Kogo Kyoko , Goda Tadashi , Funahashi Masahiro , Hanna Jun-ichi
Published: July 2002

Liquid crystal cells containing a homogeneously aligned calamitic liquid crystalline semiconductor, 2-(4-octylphenyl)-6-dodecyloxynaphthalene, doped with dyes such as 3-(2-benzothiazolyl)7-diethylaminocoumarin, emitted a visible light when a dc bias was applied. This light emission occurred irrespective of phase, and polarized light emission was well established in the Smectic B phase. The unique features of the calamitic liquid crystalline semiconductors are also discussed from a practical viewpoint.
Reduction of precursor decay anomaly in single crystal lithium fluoride
Authors: Sano Yukio
Published: July 2002

The purpose of this study is to reveal that the precursor decay anomaly in single crystal lithium fluoride is reduced by Sano's decay curve [Y. Sano, J. Appl. Phys. 85, 7616 (1999)], which is much smaller in slope than Asay’s decay curve [J. R. Asay, G. R. Fowles, G. E. Duvall, M. H. Miles, and R. F. Tinder, J. Appl. Phys. 43, 2132 (1972)]. To this end, strain, particle, velocity, and stress in a precursor and near the leading edge of the follower changing with time along Sano's decay curve are first analyzed quantitatively. The analysis verified the existence of degenerate contraction waves I and II and a subrarefaction wave R′, and the decay process [Y. Sano, J. Appl. Phys. 77, 3746 (1995)] caused in sequence by evolving followers C, I, II, R′, Rb. Next, inequalities relating decay rates qualitatively to plastic strain rates at the leading edge of the follower, which are derived using the properties of the followers, are incorporated into the analysis. Calculation results showed that the plastic strain rates were reduced by low decay rates. This indicates that the precursor decay anomaly might be greatly reduced by Sano's decay curve.
Inelastic effects in Cr–Cr2O3–Pb–SnxOy–Pb double tunnel structures
Authors: Stepurenko Yu. I. , Shaternik V. E. , Rudenko É. M.
Published: July 2002

Cr–Cr 2 O 3 –Pb–Sn x O y – Pb double tunnel junctions in which inelastic tunneling processes occur, are fabricated. The change in the superconducting order parameter in the middle Pb film upon variation of the temperature, film thickness, and resistivity of the Cr2O3 layer is investigated. The results are interpreted in the framework of theoretical models developed by Kirtley, Seidel, Grajcar, and others for inelastic tunneling processes.
Point-contact-spectroscopy investigation of the Kondo size effect in CuCr and AuFe alloys
Authors: Fisun V. V. , Yanson I. K. , Mydosh J. A. , van Ruitenbeek J. M.
Published: July 2002

Size effects in Kondo scattering are studied on CuCr and AuFe alloys (TK=2 K and 0.2 K, respectively) by applying point-contact spectroscopy in break-junction type contacts. It is shown that as the contact diameter is decreased under the condition of ballistic electron transport, the size effect enhances the interaction of the conduction electrons with the Kondo impurity (as compared to the phonons) and increases the Kondo temperature in the contact region. In an external magnetic field the size effect decreases the negative magnetoresistance in CuCr and suppresses the Kondo peak splitting in AuFe.
Low-temperature pyroelectricity in thermodynamically nonequilibrium media
Authors: Novik V. K. , Gavrilova N. D.
Published: July 2002

The temperature dependence of the pyroelectric coefficient γσ(T) of pyroelectrics in thermodynamic equilibrium at T→0 varies in accordance with Nernst’s theorem by the law γσ(T)∝Tn⩾3, which means a sharp drop in γσ(T) for T<1.5 K and precludes the efficient use of pyroelectrics in technical applications. It is shown experimentally that this fundamental limitation does not apply to thermodynamically nonequilibrium polar media, for which γσ(T)≅const for T<1.5 K.
Physical aspects of matrix isolation technique: FTIR studies on CO and CO2 in O2 and N2 matrices
Authors: Minenko M. , Vetter M. , Brodyanski A. P. , Jodl H. J.
Published: July 2002

The matrix isolation technique is traditionally used to investigate the properties of the matrix-isolated species themselves or to solve some special questions of the theory of defects in solids. We showed here that the optical spectroscopy of real matrix-isolated molecules can be successfully used to investigate the host crystal qualities, too. We demonstrated the capacity of modern FTIR spectroscopy to study the properties of cryocrystals such as phase transitions, solubility boundaries, orientational order parameter, etc., by monitoring the behavior of the IR-active molecules, which are present in matrices under investigation as a natural contamination (40 ppb). Due to the excellent optical quality of our crystal samples, we were able to determine a part of the binary phase diagram CO–O2 (at CO concentrations less than 1 ppm) as well as to investigate the kinetics of phase transitions. Furthermore, we successfully used the spectroscopy of the matrix-isolated molecules to proof that the α-β phase transition of the matrix crystal (O2) is of first order.
Low-temperature anomalies in the magnetic and thermal properties of molecular cryocrystals doped with oxygen impurity
Authors: Freiman Yu. A. , Tretyak S. M. , Jeżowski A.
Published: July 2002

The magnetic properties of oxygen pair clusters are investigated theoretically for different cluster geometries which can be realized by doping molecular cryomatrices with oxygen. Anomalous temperature and pressure behavior of the magnetic susceptibility, heat capacity, and entropy is predicted. It is proposed to use these anomalies for studying the parameters characterizing the oxygen clusters and the parameters of the host matrix: the effective spin-figure interaction constant D for the molecule in the matrix, the exchange parameter J, and the number of pair clusters Np, which can deviate markedly from the purely random value Np=6Nc2 (N is Avogadro’s number, and c is the molar concentration of the impurity). The data on the magnetic susceptibility may be used to analyze the character of the positional and orientational short-range order in the solid solution. The value of D contains information about the orientational order parameter; the distance and angular dependence of the exchange interaction parameter are still subject to discussion in the literature. The temperature dependence of Np contains information about diffusion and clusterization processes in the system.
Point sink flow in a linearly stratified fluid of finite depth
Authors: Kataoka Takeshi , Tsutahara Michihisa , Tanaka Masaya
Published: July 2002

The evolution of selective withdrawal through a point sink of horizontally unbounded, linearly stratified fluid of finite depth is studied as an initial-value problem. Following the initiation of discharge from the sink, internal gravity wave modes propagate radially upstream to change the flow pattern. These modes are called cylindrical modes. We first consider the case of F→0 (where F is the Froude number) to get linearized governing equations, and seek a linear asymptotic solution for large times t* after starting the discharge, of the cylindrical modes in a stratified fluid where viscous and diffusive effects are negligible. The obtained solution shows that the strength of the modal front grows like t*1/3, unlike the case of two-dimensional modes whose strength at the front is kept constant. Numerical calculations are also performed to study the case of F>0. The results then indicate that all the cylindrical modes can propagate upstream for any F except infinity. The steady-state withdrawal-layer thickness and time to steady state are also investigated over the full parameter range considering the viscous and diffusive effects. The obtained results are then compared with both the analytical and experimental results of prior works.
Volumetric Ion Interaction Parameters for Single-Solute Aqueous Electrolyte Solutions at Various Temperatures
Authors: Krumgalz Boris S. , Pogorelsky Rita , Sokolov Alex , Pitzer Kenneth S.
Published: July 2002

The ion interaction approach developed by Pitzer allows the prediction of thermodynamic characteristics of mixed electrolyte solutions at various temperatures, if the respective parameters for each type of single electrolyte solution are known. Among such thermodynamic characteristics are the volumetric ones (density and apparent molal volumes). A database for the densities and the apparent molal volumes versus concentrations was developed at a temperature interval of 288.15–368.15 K using all available literature sources for each single electrolyte solution formed by various electrically neutral combinations of the following ions (Na+, K+, Mg2+, Ca2+, Sr2+, Ba2+, Cl−, Br−, HCO3−, CO32−, and SO42−). These are the most important ions for industrial solutions as well as for natural waters. Statistical treatment was applied to this database in order to discard poor data. The proper treatment of all sound quality apparent molal volumes, in a wide range of concentrations from infinite dilution through saturation, allowed us to compute sets of volumetric ion interaction parameters (V̄MX0, βMX(0)V, βMX(1)V, βMX(2)V, and CMXV) at various temperatures in a 288.15–368.15 K temperature interval. The validity of the selected sets at various temperatures was demonstrated by a comparison of the experimental and calculated densities for multiple-solute electrolyte solutions containing NaCl, KCl, MgCl2, and CaCl2 with an ionic strength reaching 9.23 that resembled Dead Sea water.
Static dielectric permittivity in gapless solid solutions Hg1−xCdxTe
Authors: Prozorovskiı̆ V. D. , Reshidova I. Yu. , Puzynya A. I.
Published: July 2002

Results are presented from a comprehensive study of helicon interferometry, nonresonant cyclotron absorption, and the Shubnikov–de Haas effect at microwave frequencies in the compound HgTe and in Hg1−xCdxTe solid solutions. Analysis of the experimental results and the already existing theoretical concepts suggests that in the gapless semiconductor HgTe and its solid solutions the static dielectric permittivity εs depends on the concentration of conduction electrons and the band parameters. Anomalous behavior of εs(x) is observed in the concentration interval 0.155⩽x⩽0.2 and is attributed to a change in the structure of the edges of the conduction and valence bands in Hg1−xCdxTe.
Fractional and split crowdions in complex crystal structures
Authors: Natsik V. D. , Smirnov S. N. , Nazarenko E. I.
Published: July 2002

An analysis is made of the existence conditions and dynamical features of crowdion excitations in crystals with a complex structure of the crystalline field forming the crowdions in close-packed atomic rows. The crystalline matrix is assumed to be absolutely rigid, and the description of the crowdions therefore reduces to analysis of the generalized Frenkel–Kontorova model and the Klein–Gordon nonlinear differential equation corresponding to it. The cases of the so-called double-well and double-barrier potentials of the crystalline field are studied in this model: the structures of subcrowdions with fractional topological charges and of split whole crowdions are described, as is the asymptotic decay of split crowdions into subcrowdions when the double-barrier potential is transformed into a double well. The existence conditions of special types of subcrowdions are discussed separately; these conditions involve the atomic viscosity of the crystal and the external force applied to it. The qualitative analysis presented does not presuppose an exact solution of the Klein–Gordon nonlinear equation in explicit form. The results of this study generalize the conclusions reached previously in a study of certain particular cases of exactly solvable Klein–Gordon equations with complex potentials. The results of this study may be used not only in the physics of crowdions but also in other branches of nonlinear physics based on the Frenkel–Kontorova model.
Dynamic dielectric susceptibility tensor of a randomized f–d magnet
Authors: Beznosov A. B. , Orel E. S.
Published: July 2002

The magnetic contribution to the dynamic dielectric susceptibility tensor χαβ(ω)=χ1αβ(ω)+iχ2αβ(ω) of a system of randomized quasilocal optical dipoles of a magnetic conductor is calculated by the method of two-time retarded Green’s functions. The spectrum of χαβ(ω) consists of a coherent component χcohαβ and an incoherent component χincohαβ which are formed by electronic excitations with zero and arbitrary quasimomentum, respectively. Far from the resonance frequencies (where χ is represented by only a dispersion part) the off-diagonal components χ2α≠β(ω) are linear to leading order in the effective field ΔM=ζ/2−μBH0 (ζ is the spin–orbit interaction constant, μB is the Bohr magneton, and H0 is the magnetic field), whereas the magnetic contribution to the diagonal components χ1αα(ω) is quadratic in ΔM.