Single Breaks Research Articles

The Impact of Natural Gas Revenue on Economic Growth in Tanzania

This article investigates the linkage between natural gas revenue and economic growth in Tanzania from 2005q1 to 2017q2 periods. The study uses unit root analysis, Gregory Hansen (GH) cointegration test, autoregressive distributed lag (ARDL) bound cointegration test, and the error correction model (ECM). The Zivot and Andrews (ZA) and Clemente-Montares-Reyes (CMR) unit root tests reveal that the series had a mixed order of integration, i.e., I(0) and I(1) with a single structural break. The GH cointegration test suggests that the break date is 2012q1. Both GH and ARDL bound cointegration tests indicate that a long-run relationship exists. The empirical results show that natural gas revenues stimulate economic growth in Tanzania both in the long-run and short-run. Thus, it validates the non-existence of the resource curse hypothesis. Moreover, since the government’s share of revenues increase with gas prices, the study recommends stimulating more economic growth by promoting more uses of natural gas in other sectors of the economy—i.e., industry, transport and households—where gas prices are high. Tanzania must also soon decide on an export-oriented liquefied natural gas (LNG) project to fetch a competitive gas price.

Adaptive Response of Peripheral Blood Lymphocytes in Medical Radiation Workers using the Comet Assay: A Preliminary Studyomet Assay: A Preliminary Study

Background: Gamma irradiation can cause DNA damage in single and double-strand breaks (SSBs & DSBs), especially in peripheral blood lymphocytes. Radiotherapy medical radiation workers can be exposed to gamma radiation related to their daily work. The comet assay is a sensitive method for analyzing DNA damage, especially SSBs. This study explores DNA damage in medical radiation workers’ peripheral blood lymphocytes as an adaptive response using the comet assay.Methods: Blood samples were obtained from four radiotherapy medical radiation workers as a case study (MRW) and two non-medical radiation workers as controls, and then irradiated with various doses of 0, 1, 1.5, and 2 Gy. Lymphocytes were isolated by histopaque and processed by comet assay on the slide under alkaline conditions. The imaging results were analyzed using the Casplab_1.2.3b2 software. The comet assay parameters observed were Tail Length (TL), % Tail DNA (T.DNA), Tail Moment (TM), and Olive Tail Moment (OTM). The one-way ANOVA method was used to analyze statistically between treatment groups. Results: Based on the study results, an increase in TL, T.DNA, TM, and OTM values in all samples was directly proportional to the increase in radiation dose. However, there was no significant difference (P > 0.05) between the MRW group and the control group on each parameter of the comet assay.Conclusions: From this study, it can be concluded that the level of DNA damage of lymphocyte cells as part of the adaptive response in the MRW and control groups was relatively similar after exposure at doses of 0, 1, 1.5, and 2 Gy.

Sperm DNA damage in men with spinal cord injury: the relative incidence of single- and double-strand DNA breaks.

Men with spinal cord injury (SCI) show a high proportion of sperm DNA damage in their ejaculate but the underlying pathology remains elusive. To investigate the relative incidence of single (SSBs) and double-strand DNA breaks (DSBs) and DNase activity in men with SCI. This study included ejaculates of 20 men with SCI and 27 normozoospermic (sperm donors). A TwoTails comet assay (TTComet) allowed visualization of three categories of sperm DNA damage corresponding to SSBs, DSBs and those with a combination of SSBs and DSBs, facilitating accurate calculation of the total proportion of SSBs and DSBs. A subset of 15 individuals (sperm donors and SCI patients) was used to test for DNase activity in the seminal plasma. While the proportion of DSBs in men with SCI (median-57.5%) was higher (P=0.000) than normozoospermic samples (median-4.6%), the proportion of SSBs was higher (P=0.022) in the normozoospermic ejaculates (median-6.0%) compared to men with SCI (median-2.5%). The relative proportion of the total DSBs with respect to the total SSBs was 3.3× in men with SCI but 0.9× in normozoospermic samples. We further confirmed the high DNase activity in the seminal plasma of men with SCI. The TTComet assay provided new insights to the pathology of sperm DNA in men with SCI and may have diagnostic value in developing sperm selection methodologies to reduce DSBs prior to ART. Men with SCI are characterized by a high proportion of sperm with DSBs and high levels of DNase activity in the seminal plasma compared to normozoospermic men.

Toward achieving sustainable development agenda: Nexus between agriculture, trade openness, and oil rents in Nigeria

Abstract Over the years, agriculture has been considered as a panacea for long-term economic growth as believed by the physiocracy school of thought. Aligning this with the United Nations’ Sustainable Development Goals (specifically UN-SDG-2 which highlights zero hunger), the present study empirically complements existing studies by exploring the interactions between agriculture, trade openness, and oil rents using annual time frequency series data from 1981–2017. A series of analyses is conducted. First, a battery of non-stationarity and stationarity unit root tests are performed; these range from the traditional Augmented Dickey-Fuller (ADF) and Phillips–Perron (PP) techniques to the relatively recent Zivot Andrews (ZA) unit root test which accounts for a single structural break to ascertain stationarity properties in the variables under review. Subsequently, the recent Bayer–Hanck cointegration test in conjunction with the Johansen cointegration test was used for the cointegration analysis. Furthermore, to detect the direction of causality, the Toda-Yamamoto Granger Causality test alongside the impulse response function technique shows insightful outcomes. From the empirical results, cointegration is apparent and a long-run equilibrium relationship is traced between the outlined variables over the investigated period. The causality results and impulse response analysis highlight the existence of one-way causality links running from agriculture to trade and from trade to oil rents. The causality test results are informative, and the plausible explanation might be due to the dwindling oil market prices. More insights are elucidated in the conclusion section accordingly.

Cytotoxic Evaluation of <i>Eurycoma longifolia</i> Jack Root Extract on Chromosome Aberrations in Human Lymphocytes <i>In vitro</i>

This study aimed to investigate chromosomal aberrations of Eurycoma longifolia Jack (EL) root extract in human lymphocytes in vitro. Human whole blood was cultured in medium solution that treated with distilled water, 20% DMSO, extract of EL roots at the concentration of 2.5, 5, 10, 20, 40, 80 µg/mL (extracted with distilled water and ethanol), and nontreated (blank: only culture medium and whole blood). All experiments were cultured for 72 hours in the 37°C incubator. The effects of EL roots extract on cytotoxicity were compared with the control groups including the blank, distilled water, and 20% DMSO. This study found that EL root extract significantly decreased metaphase cell number and increased chromosome aberrations dose dependent manner (p<0.01). The 7 types of chromosome aberration that were observed consisted of dicentric chromosome, single chromatid breaks, isochromatid break, isochromatid gap, single chromatid gap, fragmentation, and deletion. The dicentric chromosome was the most common chromosomal aberrations type that was treated with EL root extract both distilled water and ethanol. Moreover, the ethanolic extract of EL root was more effective to stimulate chromosome aberrations compared to the water extract of EL root (the deletion and fragmentation were not found in the water extract of EL root). This study demonstrated that the phytochemicals of EL root extract had cytotoxicity effect (decreased metaphase cells and increase cells death) and genotoxic effect (increased chromosomal aberrations. The use of EL root crude extract with distilled water is therefore safer for cells. However, when EL is used at high levels, it may lead to the inhibition of cell division process and cause side effects (toxicity). EL extracts consist of various phytochemicals with different properties and dosages, thus more studies should be conducted on the effect of those substances on cytotoxicity, especially their effects on genotoxicity humans.

ASAP5: A predictive PDK for the 5 nm node

We present a predictive process design kit (PDK) for the 5 nm technology node, the ASAP5 PDK. ASAP5 is not related to a particular foundry and the assumptions are derived from literature. It incorporates several innovations that the semiconductor industry has adopted to address scaling challenges, improve reliability and performance. These include contact over active gate (COG), fully self-aligned vias (FSAVs), single diffusion breaks (SDBs), and cobalt interconnects. We discuss implications of these changes in the context of standard cell and static random access (SRAM) bit cells. Interconnect modelling is improved and incorporates the effects of metal fill and barrier geometry on line resistivity. Different metal fill and barrier configurations are compared to determine the PDK interconnect stack. We discuss design rule assumptions for the key layers. The PDK uses horizontal nanowire field-effect transistors (NWFETs) for better ON and OFF-state performance. The transistor compact models are calibrated to the 3-D technology computer-aided design (TCAD) simulation results.

Genome editing using preassembled CRISPR-Cas9 ribonucleoprotein complexes in Fusarium graminearum.

Genome editing using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has greatly facilitated the genetic analysis of fungal pathogens. The head blight fungus, Fusarium graminearum, causes destructive losses of economically important cereal crops. The recent development of the CRISPR-Cas9 system for use with F. graminearum has enabled more efficient genome editing. In this study, we described a CRISPR-Cas9-based genome-editing tool for the direct delivery of preassembled Cas9 ribonucleoproteins (RNPs) into the protoplasts of F. graminearum. The use of RNPs significantly increased both the number of transformants and percentage of transformants in which the target gene was successfully replaced with a selectable marker. We showed that a single double-strand DNA break mediated by the Cas9 ribonucleoprotein was sufficient for gene deletion. In addition, short-homology recombination required only 50 base pair regions flanking the target gene. The high efficiency of Cas9 RNPs enables large-scale functional analysis, the identification of essential genes, and gene deletion that is difficult with conventional methods. We expect that our approach will accelerate genetic studies of F. graminearum.

Inactivation of SARS-CoV-2 by charged particles for Future Vaccine Production Applications: A Monte Carlo study

The world is still suffering from the SARS-CoV-2 pandemic, and the number of infected people is still growing in many countries in 2022. Although great strides have been made to produce effective vaccines, efforts in this field should be accelerated, particularly due to the emergence of new variants. Using inactivated viruses is a conventional method of vaccine production. High levels of ionizing radiation can effectively inactivate viruses. Recently, studies on SARS-CoV-2 irradiation using low-LET radiations (e.g., gamma rays) have been performed. However, there are insufficient studies on the impact of charged particles on the inactivation of this virus. In this study, a realistic structure of SARS-CoV-2 is simulated by using Geant4 Monte Carlo toolkit, and the effect of electrons, protons, alphas, C-12, and Fe-56 ions on the inactivation of SARS-CoV-2 is investigated. The simulation results indicated that densely ionizing (high-LET) particles have the advantage of minimum number of damaged spike proteins per single RNA break. The RNA breaks induced by hydroxyl radicals produced in the surrounding water medium were significant only for electron beam radiation. Hence, indirect RNA breaks induced by densely ionizing particles is negligible. From a simulation standpoint, alpha particles (with energies up to 30 MeV) as well as C-12 ions (with energies up to 80 MeV/n), and Fe-56 ions (with any energy) can be introduced as particles of choice for effective SARS-CoV-2 inactivation.

Outcomes of 25-gauge pars plana vitrectomy alone with air tamponade for the management of rhegmatogenous retinal detachment with inferior breaks

BackgroundThis study was investigated the surgical outcomes of primary rhegmatogenous retinal detachment (RRD) with inferior retinal breaks (IRBs) that were repaired by 25-gauge pars plana vitrectomy (PPV) with air tamponade.MethodsThis retrospective review included 81 consecutive patients who had RRD with IRBs and underwent PPV with air tamponade in our hospital from January 2017 to January 2020. The main outcomes were single surgery anatomical success (SSAS) rate, postoperative best-corrected visual acuity (BCVA), and complications.ResultsThe patient population consisted of 29 women and 52 men (mean age, 52.12 years); the mean follow-up interval was 8.88 months. The mean number of affected quadrants was 1.65 (range, 1–4 quadrants) and the mean number of breaks was 3.25. A single break was present in 20 cases (24.7%); two to 10 breaks were present in 61 (75.3%) cases. The SSAS rate was 91.36% (74/81) and the final anatomical success rate was 96.30% (78/81). More than half of the patients had BCVA < 0.3 logarithm of the minimum angle of resolution at the last follow-up. Axial length and patient age were candidate risk factors for redetachment (axial length, p = 0.03; age, p = 0.002). Postoperative complications included macular epiretinal membrane formation in one patient, lens opacity in three patients, and clinically significant macular edema in one patient.ConclusionsPPV with air tamponade may be effective for the treatment of primary RRD with IRBs. Extensive preoperative discussion may be necessary for young patients and patients with particularly long axial length.

Parameters design of voltage sharing components for the series multi‐break mechanical switch

Series multi-break mechanical switch is one of the critical components of high-voltage hybrid DC circuit breakers. However, due to the existence of distributed capacitance, the voltage distribution between the breaks is not balanced. This paper proposed a voltage sharing configuration method of the mechanical switch of hybrid DC circuit breaker, and carried out the static DC voltage and the transient voltage distribution characteristics tests to verify its effectiveness. Considering the influence of whole structure of the circuit breaker, this paper established the electrostatic field model and circuit simulation model of a typical ±535-kV hybrid DC circuit breaker. And it analyzed the influence of single break's opening fault, breaking open distance, and the shielding fitting on the voltage distribution characteristics of series six break mechanical switch. According to the simulation results based on the Zhangbei voltage source converter-based high-voltage direct current project type test parameters, the parameters design of the voltage sharing components of the mechanical switch are obtained, which can meet the voltage sharing coefficient requirement of 95%.

Pneumatic retinopexy versus scleral buckling for the management of primary rhegmatogenous retinal detachment.

To compare pneumatic retinopexy (PnR) and scleral buckling (SB) for repair of primary rhegmatogenous retinal detachment. Single-centre retrospective analysis of patients undergoing PnR and SB. Inclusion criteria comprehend phakic patients with a single retinal break or a group of breaks in detached retina in the same quadrant above the 8- and 4-o'clock meridians. A total of 184 patients were included, respectively 106 underwent PnR and 78 SB. Follow-up time was 6 months. Final visual outcome did not differ significantly between the two procedures (P = 0.12). Single-procedure reattachment rate was significantly higher in SB (94%) than in PnR (68%) (P < 0001). Anatomical success rate was not influenced by macular involving. Reattachment rate in repeated PnR was 95% and in these patients visual outcome did not statistically differ compared to those reattached with first attempt (P = 0.196). Total reattachment rate including repeated procedures was 87% in PnR group and 94% in SB group, the difference was not significant (P = 0.06). SB has a higher single reattachment rate than PnR. However, final visual outcomes of both procedures are comparable. In selected cases, PnR can be repeated with a high successful rate.

IDENTIFICATION OF SECRETORY CARCINOMA IN ARCHIVAL MATERIAL BY HISTOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL METHODS WITH MOLECULAR PROFILING OF ETV6 AND RET ON ALTERNATIVELY DIAGNOSED SALIVARY GLAND TUMORS

<h3>Introduction</h3> Secretory carcinomas (SC) of minor and major salivary gland (SG) are rare neoplasms that demonstrate microscopic overlap with acinic cell carcinomas (ACC), adenocarcinoma NOS (AdNOS), and mucoepidermoid carcinomas (MEC) respectively. Recently alternative translocations of ETV6-RET gene locus have been recognized in a small group of SC. This study aims to identify previously undiagnosed SC, from the archival cases of tumors signed out as other salivary malignancies and identify the novel ETV6 and RET genes by Fluorescence in situ hybridization (FISH). <h3>Materials and Methods</h3> We performed a retrospective search of ACC, AdNOS and MEC within the annals of the UF, Oral Pathology Biopsy service from 2000-2020. Inclusion criterion using histopathological characteristics of SC were created. A total of 205 cases encompassing ACC, AdNOS and MEC were retrieved. All cases were screened with established histologic criteria and were stained (IHC) with S100 and mammaglobin. FISH was performed on one case with sufficient tissue for testing to evaluate the presence of ETV6-RET fusion. <h3>Results</h3> Ten out of 205 cases met the histologic inclusion criteria. Five out of these ten cases were positive for S100 and mammaglobin confirming the diagnosis of SC. These cases were previously diagnosed as AdNOS (n=2), ACC (n=2) and MEC (n=1) respectively. Most of the SC in this series were seen around the 5^th decade (mean age = 55.4) and demonstrated a slight male predilection. (71.4%). Buccal mucosa was the most affected site (60%), followed by hard palate and soft palate (40%). A single break apart probe of both ETV6 translocation and chromosomal deletion of RET was established in the tested case. <h3>Conclusion</h3> SC is a recently accepted salivary gland neoplasm. Our study strengthens the understanding of this entity by assessing the histopathological features of SC and identifying a new subset of ETV6 and RET genes.

Are Stock Markets among BRICS Members Integrated? A Regime Shift-Based Co-Integration Analysis

Long-run relationships and structural breaks have often been confused so that many investigators ignore the structural breaks in long-run stock price relationships. In this paper, we investigate the long-run relationships among stock prices in BRICS countries in a bivariate framework. We used a non-linear threshold cointegration test, which endogenously incorporates possible regime shift behaviors into the long-run relationships from 2004 to 2018. The Johansen cointegration test, the Gregory and Hansen cointegration test, and the Hatemi-J regime shift cointegration test, which allow for single and double structural breaks, were used. The principal finding of this paper confirms the presence of cointegration among the BRICS stock markets with two endogenous structural breaks. The study confirms that ignoring the presence of structural breaks in long-run series data can produce ambiguous results. It also confirms the absence of cointegration among these stock markets (Brazil and China, India and China, and China and South Africa) after two endogenous structural breaks. These empirical findings support conjecture on more than just the changes in the relationships between the BRICS stock markets. The disintegrated markets suggest the absence of arbitrage activity and vice versa. Thus, disintegrated markets mean that investors can obtain long-term gains through international portfolio diversification. While the benefit of the diversification is very limited in the long run, it is unlikely to be eliminated in practice. Hence, there is a possibility of obtaining an unusual profit in such a market, and consequently the assumptions of market efficiency could also be violated.

Impact Loads on Tension Composite Multi-Strings of Insulator After a Single String Breaks

The dynamic impact load after a single insulator of a tension composite multi-strings of insulator (MSI) set has failed is a key factor that should be considered in design. In this paper, an experimental method to obtain the dynamic tensile impact factor (DTIF) is established by considering a typical double-strings set, which is commonly used in practical engineering. A nonlinear numerical simulation method based on the finite element model, which is convenient for cases that are more complex than the double-strings set, is proposed to calculate the DTIF and demonstrated through the experimental results. The values of the DTIF on the unbroken insulator string obtained by the experimental models fall between 2.6 and 3.3, which should be a very valuable reference for the design of composite MSI sets. The size of connection fittings is a key factor that influences the DTIF, and the yoke height between the insulator strings and the conductors is the most sensitive parameter. The application of the proposed method to calculate the DTIF can improve the existing design approach to ensure the safety of the tension composite MSI sets, especially for high voltage transmission lines.

A Time-Course Evaluation of DNA Damage and Neurotoxicity Induced by PEGylated Graphene Oxide Nanoparticle in Swiss Albino Mice.

PEGylated graphene oxide nanoparticle (PEG-nGO) has been commonly used as a carrier for therapeutic drugs and vaccines, because of its unique properties, such as high solubility, more stability and increased biocompatibility in physiological solutions. This study aimed to examine the DNA damage and neurotoxicity in young mice after up to 4 h of the treatment with PEG-nGO. A single dose (5 mg/kg) of intravenous injection was administered through the tail vein of adult mice. Total genomic DNA was isolated from the control and treated animals after 1 h, 2 h, and 4 h of treatments and examined for DNA damage by diphenyl assay, DNA fragmentation Assay, and FTIR (Fourier transform infrared) techniques. DNA damage studies indicated DNA fragmentation after 1 h and 2 h of treatments followed by recovery at 4 h. FTIR analysis further supported these results and showed a detailed molecular effect of the treatments that caused single and double-strand DNA breaks at 1 to 2 h after the treatments and indicated DNA damage response and recovery at 4 h. Histopathology showed neuronal apoptosis and lesions in the brain after 1 to 2 h and invasion of inflammatory response and chromatolysis after 4 h. PEG-nGO caused immediate DNA damage and cytotoxicity to the brain and its future use as a drug carrier should be considered with caution.

Quasi-maximum likelihood estimation of break point in high-dimensional factor models

This paper proposes a quasi-maximum likelihood (QML) estimator of the break point for large-dimensional factor models with a single structural break in the factor loading matrix. We show that the QML estimator is consistent for the true break point when the covariance matrix of the pre- or post-break factor loading (or both) is singular. Consistency here means that the deviation of the estimated break date from the true break date k0 converges to zero as the sample size grows. This is a much stronger result than the break fraction kˆ/T being T-consistent (super-consistent) for k0/T. Also, singularity occurs for most types of structural changes, except for a rotational change. Even for a rotational change, the QML estimator is still T-consistent in terms of the break fraction. Simulation results confirm the theoretical properties of our estimator, and it significantly outperforms existing estimators for change points in factor models.

Evaluating the Therapeutic Potential of a Small Molecule ATR Inhibitor Combined with Radiotherapy for Head and Neck Squamous Cell Carcinoma

<h3>Purpose/Objective(s)</h3> Radiotherapy (RT) plays a major role in HNSCC treatment. Unfortunately, recurrence rates approach 50% for locally advanced, HPV-negative HNSCC, and treatment options for recurrent HNSCC are limited. New therapies are needed to enhance RT response and improve local tumor control. Ataxia telangiectasia and Rad 3-related (ATR) is a DNA damage response protein activated by replication stress (common in HNSCC) and single strand DNA breaks, such as those induced by RT. We evaluated the effect of ATR inhibitor BAY1895344 (BAY) +/- RT in preclinical HNSCC models, including the radioresistant MOC2 model. <h3>Materials/Methods</h3> HNSCC cells were treated with vehicle or serial dilutions of BAY +/- 4 Gy, and IC50 was determined by MTT assay at 72h. Sensitivity of immortalized oral keratinocyte (IMOK) cells to BAY was evaluated as a normal tissue control. To evaluate inhibition of phosphorylation of ATR downstream effector CHK1, cell lysates were harvested after treatment with BAY +/- 4 Gy (1 hr post-RT) and immunoblot performed. Radiosensitization was evaluated by clonogenic assay and quantification of yH2AX foci at 1, 3, 8, and 24 hr after 4 Gy +/- 100nM BAY. Heterotopic MOC2 tumors were induced in the hind limb of C57BL/6 mice. When tumors reached 60-110 mm³, mice were randomized to vehicle, BAY, 10 Gy, or 10 Gy + BAY (n=7-12/group). BAY was given PO (30 mg/kg BID x 3d) with RT given after the 2nd dose. Tumors were measured 3x/week, and times to tumor quintupling (TTQ) compared by ANOVA with Tukey's multiple comparisons post-test. In an ongoing experiment, mice were randomized to vehicle, BAY (50 mg/kg BID 3 days on/4 days off, continued weekly), 10 Gy, or 10 Gy+BAY (n=9/group). <h3>Results</h3> BAY inhibited CHK1 phosphorylation in a dose-dependent manner and led to persistent yH2AX foci at 24h post-RT. MTT assay showed cooperative effect between BAY and RT (IC50=63 nM for BAY vs 15nM for BAY + 4Gy) in MOC2 cells, with similar results across several primary murine HNSCC cell lines and the human FaDu cell line. IMOK cells were relatively resistant to BAY (IC50=3 uM). Clonogenic assay showed radiosensitization with 100 nM BAY (RT dose enhancement ratio = 3.7 at 4 Gy for MOC2). In the MOC2 model, BAY increased <i>in vivo</i> mean TTQ by 7.4 d vs vehicle (p=0.002), and 10 Gy + BAY increased TTQ by 7.3 d vs 10 Gy alone (p<0.001). A trend towards longer growth delay was observed 10 Gy + BAY vs BAY (mean TTQ increased by 4.3 d; p=0.08). With continued BAY dosing (3d on/4d off), median TTQ was 9.3 d with vehicle, 16.8 d with RT, and not yet reached for BAY or 10 Gy + BAY. <h3>Conclusion</h3> BAY 1895344 radiosensitizes HNSCC <i>in vitro</i> and increases tumor growth delay <i>in vivo</i> as a monotherapy or in combination with RT. Given these promising preclinical results, safety and efficacy of BAY 1895344 with stereotactic body radiation therapy (SBRT) reirradiation and pembrolizumab for recurrent HNSCC will be evaluated in an ongoing phase I CTEP trial (NCT04576091).

Novel Postgate Single Diffusion Break Integration in Gate-All-Around Nanosheet Transistors to Achieve Remarkable Channel Stress for N/P Current Matching

A novel integration scheme of postgate single diffusion break (PG-SDB) has been proposed to enhance channel stress for Si gate-all-around (GAA) nanosheet field-effect transistors (NS-FET), based on TCAD simulations. Compared to conventional SDB and self-aligned SDB (SA-SDB), the proposed PG-SDB scheme implements SDB module after the replacement metal gate (RMG) process, so as to eliminate the stress relaxation to free surfaces. The channel stress has been boosted to +3.5 GPa/−4.7 GPa, for N/P NS-FETs, respectively. As a result, great drive capability as well as N/P current matching has been achieved in the PG-SDB GAA NS-FETs.

Multiple structures of laminar fuel-rich spray flames in the counterflow configuration

Multiple structures of laminar non-premixed ethanol/air spray flames in the counterflow configuration are presented which exist under fuel-rich conditions and moderate gas strain rates. A mono-disperse liquid fuel spray with carrier gas air is directed against an air stream. Two different spray flame structures are found for identical boundary and initial conditions: one of these flame structures consists of two different chemical reaction zones which reside on either side of the gas stagnation plane. In the second case, the spray-sided flame does not exist and combustion occurs entirely on the gas side of the configuration with largely distinct evaporation and combustion zones. Parametric studies of equivalence ratio between 1.1 and 1.8 and gas strain rates on the spray side of the configuration from 55/s as well as initial droplet size between 10 µm and 50 µm are performed. A regime diagram is presented to display the range of existence of the multiple/single structures as well as the flame extinction. Physical reasons for the existence and breakdown of the multiple structures are explored and discussed. The spray flame structure with a single chemical reaction zone breaks down with increased strain rate when the chemical time scales of OH and fuel vapor are equal at the crossover temperature (Tcross=1104 K) of the reaction rate constants of H + O2⇌ OH + O and H + O2 + M →HO2 + M.

Determinants of ecological footprint and PM2.5: Role of urbanization, natural resources and technological innovation

Due to rapid economic growth and development, human demand for natural resources is growing in Bangladesh, which causes climate change, loss of biodiversity, soil degradation, and environmental hazard. Few studies have been conducted to investigate the determinants of ecological footprint and air quality (PM2.5) in Bangladesh between 1990 and 2016. This paper also investigates the existence EKC hypothesis in both ecological footprint and PM2.5 case. Single structural break analysis has employed to know the break point while estimating integration of each variable. After estimating the integration, we have employed ARDL bound testing approach to co-integration to show the long run relationship among the urbanization, natural resources, population density, economic growth, ecological footprint and PM2.5. For the robustness about the long run relationship among the variables, we also employ Bayer and Hanck joint co-integration. The results from both models demonstrate that urbanization, population density and energy consumption are major determinants of ecological footprint and PM2.5. However, technological innovation and natural resources are reducing the ecological footprint and PM2.5. The both the models provide evidence of existence of EKC hypothesis in case of Bangladesh. This study also has suggested some important policy implications regarding the environmental sustainability.