Contract Time Optimization Methodologies for Highway Construction Projects

This study was conducted to develop methodologies for appropriately determining the monetary values of I/D rates of highway construction projects in Indiana. In this study, a comprehensive literature review was performed to identify possible effective methodologies for work zone effects, construction impacts, and contract time optimization. The highway production rates were developed in a previous study. The production rates were validated and adjusted with the help from INDOT field engineers. The weighin- motion (WIM) collected traffic data were obtained, processed, and analyzed to provide input data for user cost calculations at highway work zones. Construction data were obtained and processed to develop the relationship between the construction cost and construction time. With the traffic and construction data, the methods for user cost calculations were developed as the basis of determining appropriate I/D rates. User costs resulting from traffic delays at Indiana highway work zones were analyzed. A series of equations for estimating user costs at work zones were developed. User cost calculation sheets using MS Excel were developed based on the traffic data on Indiana highway network. Finally, a method was developed to determine I/D rates based on the relationship between construction cost and construction time in combination with the estimated user costs at given work zones. Guidelines for developing A+B bidding and I/D provisions were provided

Computationally Efficient DOA Tracking Algorithm in Monostatic MIMO Radar with Automatic Association

We consider the problem of tracking the direction of arrivals (DOA) of multiple moving targets in monostatic multiple-input multiple-output (MIMO) radar. A low-complexity DOA tracking algorithm in monostatic MIMO radar is proposed. The proposed algorithm obtains DOA estimation via the difference between previous and current covariance matrix of the reduced-dimension transformation signal, and it reduces the computational complexity and realizes automatic association in DOA tracking. Error analysis and Cramér-Rao lower bound (CRLB) of DOA tracking are derived in the paper. The proposed algorithm not only can be regarded as an extension of array-signal-processing DOA tracking algorithm in (Zhang et al. (2008)), but also is an improved version of the DOA tracking algorithm in (Zhang et al. (2008)). Furthermore, the proposed algorithm has better DOA tracking performance than the DOA tracking algorithm in (Zhang et al. (2008)). The simulation results demonstrate effectiveness of the proposed algorithm. Our work provides the technical support for the practical application of MIMO radar

Modeling of counter-current spontaneous imbibition in independent capillaries with unequal diameters

Spontaneous imbibition is a crucial process for oil recovery from fractured and unconventional reservoirs. Herein, with the assumption of capillaries being independent, a new mathematical model for spontaneous imbibition is proposed and solved using a numerical method. The simulated results show that the wetting phase preferentially enters smaller capillaries where the advancement velocity is higher than that in larger ones, while the non-wetting phase can be displaced out in the larger capillaries. In addition, the effect of fluid viscosity ratio on counter-current imbibition is analyzed. The results show that imbibition velocity becomes higher with the increase in the viscosity ratio. When the viscosity of the non-wetting phase is larger than that of the wetting phase, the end pressure gradually increases as the imbibition front advances. In contrast, when the viscosity of the non-wetting phase is less than that of the wetting phase, the end pressure decreases with the infiltration. With a higher viscosity ratio of non-wetting and wetting phase, the heterogeneity of the interface advancement among different capillaries increases.Cited as: Chen, K., Xu, H., Zhang, Z., Meng, Q., Zhang, T. Modeling of counter-current spontaneous imbibition in independent capillaries with unequal diameters. Capillarity, 2022, 5(6): 115-122. https://doi.org/10.46690/capi.2022.06.0

Passive control of temperature distribution in cancerous tissue during photothermal therapy using optical phase change nanomaterials

Thermal therapy is a very promising alternative treatment for benign tumor, in which the temperature control is a key issue to avoid unwanted thermal damage of healthy tissue. However, the active temperature control methods usually require the assistance of real-time and accurate temperature monitoring devices. Even though, the lag of temperature control is inevitable. Therefore, in the present work, a passive control method is proposed to improve the uniformity of temperature distribution inside tumorous tissue during laser induced thermal therapy (LITT). Optical phase change nanoparticles (O-PCNPs) are utilized to replace the commonly used noble metal nanoparticles to enhance and adjust the localized light absorption in tumor. In the early stage of LITT, the O-PCNPs is used to improve the specific absorption rate in the targeted region. However, after the local temperature reaches a certain level (phase transition temperature), the O-PCNPs convert from amorphous state to crystalline state. By carefully selecting the size, shape, and laser wavelength, the absorption cross section of O-PCNPs could drop dramatically after phase transition. Therefore, in the high temperature zone the local temperature increasing rate reduces due to the reduction of local heat generation rate. On the contrary, the temperature increasing rate rises in the low temperature zone since more energy is transferred to the deeper tissue. In the present work, results show that SiO2@VO2 nanoshells can be applied as thermal contrast agents to improve the temperature uniformity in tumor during LITT

Development and Applicability Verification of a Competency Evaluation Index System for General Practice Team Leaders

BackgroundThe general practice team leader is not only a community health practitioner, but also a manager, commander and coordinator of a general practice team. So choosing an eligible person for the post of general practice team leader is of primary importance.ObjectiveTo develop and verify a competency evaluation system for general practice team leaders, providing a reference for scientifically assessing the competencies of a general practice team leader, and for selecting an eligible person as a general practice team leader.MethodsBy use of literature review and semi-structured reviews, we collected data regarding competencies for an eligible general practice team leader, and used them to initially develop a competency evaluation system for general practice team leaders. Then from July to October 2020, we conducted a three-round Delphi survey with a purposive sample of 20 experts (in the field of general medicine, medical education, public health management, or administrative management) to improve the system, and assess the indicators of the system using the analytic hierarchy process, and test the logic consistency among indicators, then the final system was formed. To assess values of the three-level indicators in the system, from November 1 to 30, 2020, we carried out a survey on wjx.cn (an online questionnaire survey platform) using a self-administered questionnaire developed by us, and selected a stratified random sample of 32 cases (16 directors of community health centers, and 16 general practice team leaders from 8 central urban districts of Shanghai) to anonymously complete the survey via scanning the WeChat RQ code using a mobile phone or computer. The survey data were collected to input into a database, and analyzed for understanding the inter-rater differences in the importance of the top 15 indicators.ResultsThe response rate, authority coefficient, and Kendall's W were 90.0%, 0.912, and 0.183 (χ2=42.516, P<0.001) respectively, for the first round of survey, 95.0%, 0.933, and 0.359 (χ2=68.937, P<0.001) respectively, for the second round of survey, and 100.0%, 0.940, and 0.516 (χ2=87.329, P<0.001) , respectively, for the third round of survey. The final system is composed of 5 first-level indicators, 17 second-level indicators and 43 third-level indicators. The weights for the 5 first-level indicators were 0.344, 0.222, 0.192, 0.137 and 0.105, respectively. The consistency ratios for hierarchical arrangement of indicators were all <0.1. Among the top 15 third-level indicators in terms of importance, except for the importance of "the ability to provide referral services", and "the ability to assist in the handling and management of public health events", the importance of other 13 indicators rated by directors of community health centers and general practice team leaders showed no significant differences (P>0.05) .ConclusionThe system developed by us has high scientificity and practicability with a rational structure and well-targeted indictors, which may be used as a tool for the selection and training of general practice team leader

Cross-Reactive Human IgM-Derived Monoclonal Antibodies that Bind to HIV-1 Envelope Glycoproteins

Elicitation of antibodies with potent and broad neutralizing activity against HIV by immunization remains a challenge. Several monoclonal antibodies (mAbs) isolated from humans with HIV-1 infection exhibit such activity but vaccine immunogens based on structures containing their epitopes have not been successful for their elicitation. All known broadly neutralizing mAbs (bnmAbs) are immunoglobulin (Ig) Gs (IgGs) and highly somatically hypermutated which could impede their elicitation. Ig Ms (IgMs) are on average significantly less divergent from germline antibodies and are relevant for the development of vaccine immunogens but are underexplored compared to IgGs. Here we describe the identification and characterization of several human IgM-derived mAbs against HIV-1 which were selected from a large phage-displayed naive human antibody library constructed from blood, lymph nodes and spleens of 59 healthy donors. These antibodies bound with high affinity to recombinant envelope glycoproteins (gp140s, Envs) of HIV-1 isolates from different clades. They enhanced or did not neutralize infection by some of the HIV-1 primary isolates using CCR5 as a coreceptor but neutralized all CXCR4 isolates tested although weakly. One of these antibodies with relatively low degree of somatic hypermutation was more extensively characterized. It bound to a highly conserved region partially overlapping with the coreceptor binding site and close to but not overlapping with the CD4 binding site. These results suggest the existence of conserved structures that could direct the immune response to non-neutralizing or even enhancing antibodies which may represent a strategy used by the virus to escape neutralizing immune responses. Further studies will show whether such a strategy plays a role in HIV infection of humans, how important that role could be, and what the mechanisms of infection enhancement are. The newly identified mAbs could be used as reagents to further characterize conserved non-neutralizing, weakly neutralizing or enhancing epitopes and modify or remove them from candidate vaccine immunogens