Optimal dispatch of uncertain energy resources

The future of the electric grid requires advanced control technologies to reliably integrate high level of renewable generation and residential and small commercial distributed energy resources (DERs). Flexible loads are known as a vital component of future power systems with the potential to boost the overall system efficiency. Recent work has expanded the role of flexible and controllable energy resources, such as energy storage and dispatchable demand, to regulate power imbalances and stabilize grid frequency. This leads to the DER aggregators to develop concepts such as the virtual energy storage system (VESS). VESSs aggregate the flexible loads and energy resources and dispatch them akin to a grid-scale battery to provide flexibility to the system operator. Since the level of flexibility from aggregated DERs is uncertain and time varying, the VESSs’ dispatch can be challenging. To optimally dispatch uncertain, energy-constrained reserves, model predictive control offers a viable tool to develop an appropriate trade-off between closed-loop performance and robustness of the dispatch. To improve the system operation, flexible VESSs can be formulated probabilistically and can be realized with chance-constrained model predictive control. The large-scale deployment of flexible loads needs to carefully consider the existing regulation schemes in power systems, i.e., generator droop control. In this work first, we investigate the complex nature of system-wide frequency stability from time-delays in actuation of dispatchable loads. Then, we studied the robustness and performance trade-offs in receding horizon control with uncertain energy resources. The uncertainty studied herein is associated with estimating the capacity of and the estimated state of charge from an aggregation of DERs. The concept of uncertain flexible resources in markets leads to maximizing capacity bids or control authority which leads to dynamic capacity saturation (DCS) of flexible resources. We show there exists a sensitive trade-off between robustness of the optimized dispatch and closed-loop system performance and sacrificing some robustness in the dispatch of the uncertain energy capacity can significantly improve system performance. We proposed and formulated a risk-based chance constrained MPC (RB-CC-MPC) to co-optimize the operational risk of prematurely saturating the virtual energy storage system against deviating generators from their scheduled set-point. On a fast minutely timescale, the RB-CC-MPC coordinates energy-constrained virtual resources to minimize unscheduled participation of ramp-rate limited generators for balancing variability from renewable generation, while taking into account grid conditions. We show under the proposed method it is possible to improve the performance of the controller over conventional distributionally robust methods by more than 20%. Moreover, a hardware-in-the-loop (HIL) simulation of a cyber-physical system consisting of packetized energy management (PEM) enabled DERs, flexible VESSs and transmission grid is developed in this work. A predictive, energy-constrained dispatch of aggregated PEM-enabled DERs is formulated, implemented, and validated on the HIL cyber-physical platform. The experimental results demonstrate that the existing control schemes, such as AGC, dispatch VESSs without regard to their energy state, which leads to unexpected capacity saturation. By accounting for the energy states of VESSs, model-predictive control (MPC) can optimally dispatch conventional generators and VESSs to overcome disturbances while avoiding undesired capacity saturation. The results show the improvement in dynamics by using MPC over conventional AGC and droop for a system with energy-constrained resources

EGFR Targeted Nanocarriers for Cancer Diagnosis and Therapy

Conventional cancer management is directly associated with many problems, including accurate therapeutic delivery to tumours and serious side effects of chemotherapeutics. A specific and efficient anticancer delivery to the tumour site without damaging normal tissues is the ultimate goal of all cancer treatment strategies. Nanomedicine has immense potential for cancer therapy that focuses on improving treatment efficacy, while reducing toxicity to normal tissues as well. However, the biodistribution and targeting capability of nanoparticles lacking targeting ligands rely solely on their physicochemical properties and the pathophysiological parameters of the body. Targeting is a promising strategy for selective and efficient therapeutic delivery to tumour cells with reduced detrimental side effects. Taking advantage of the fact that molecular markers and receptors over-express on the tumour cell surface as compared to a normal cell, the active targeting approach would be beneficial for cancer therapy. The epidermal growth factor receptors (EGFR), abnormally overexpressed in many epithelial tumours, have received much attention for molecular targeting in cancer diagnostics and therapeutics. This review presents the role of EGFR targeting in cancer imaging and therapy, and some recent researches on treatment of EGFR overexpressing cancers by using targeted nanoparticulate platforms. It also discusses illustrative examples of various ligands, including antibodies, antibody fragments, nanobodies, and peptides.HighlightsHighlights the potential of EGFR targeted nanocarriers for cancer diagnosis and therapy.Summarizes the role of EGFR targeting in cancer therapy.Describes various examples of recent researches on EGFR targeted nanocarriers.Explains illustrative examples of various ligands for EGFR targeting.

PENGARUH PEMANFAATAN LIMBAH GENTENG SEBAGAI CAMPURAN AGREGAT KASAR PADA BETON NORMAL

Beton banyak digunakan secara luas sebagai bahan bangunan. bahan tersebut diperoleh dengan cara mencampurkan semen portland, air,agregat kasar dan skali-kali mengunakan agregat tambahan, pada penelitian ini mengunakan bahan tambahan limbah genteng pres kodok atau genteng karang sebagai agregat kasar, berat genteng rata-rata 1,2 kg/ biji , permukaan genteng atau tekstur genteng halus, sifat genteng anti perembesan air 0,2-0,3%. Tujuan penelitian ini adalah untuk mengatahui pengaruh penambahan limbah genteng sebagai pengganti agregat kasar pada beton normal. Penelitian ini dimulai dengan pengujian terhadap material penyusun beton dan membuat rancangan adukan atau mix design berdasarkan metode SNI 03-7656-2012 tentang beton normal. Mutu beton yang direncanakan 20 MPa, selanjutnya adalah pembuatan benda uji berbetuk silinder dan double-L sebanyak 45 buah dengan variasi 0%, 25%, 50%, 75%, dan 100%. Pengujian beton dilakukan setelah 28 hari perendaman. Penelitian ini dilakukan di Laboratorium Program Studi Teknik Sipil Fakultas Teknik Universitas Muhammadiyah Mataram. Beton yang menggunakan campuran limbah genteng didapatkan kuat tekan tertinggi 24,395 MPa pada variasi 25% dan 12,368 MPa pada variasi 100% menjadi yang terendah, pada variasi 25% kuat tekan memenuhi standar beton normal yaitu 20 MPa, pada pengujian kuat tarik belah dan kuat geser mengalami penurunan namum masih memenuhi standar untuk kuat tarik belah dari 1,6- 3 MPa dan standar kuat geser yaitu 4-17 MPa, semua campuran mengalami penurunan dikarenakan bahan utama limbah genteng adalah tanah liat merah banyak menyerap air, mudah hancur dan berat jenis genteng yang lebih ringan dari kerikil. sehingga campuran variasi yang mengalami deformasi dan membuat kuat tekan, kuat tarik belah dan kuat geser beton semakin berkurang

Effects of conflicts and government interventions on food security in Kano, Nigeria

Majority of households in Kano are facing serious food security challenges, due to high rate of poverty, Boko Haram/Farmers-herders conflicts and neglect of government roles in the agriculture sector. The objectives of the study are to assess the status of household food security; to analyze factors (socioeconomic variables, conflicts and government interventions) influencing food security status; and to identify the coping strategies adopted by the food insecure households in Kano, Nigeria. A face-to-face survey of 426 household heads from three regions in Kano was conducted using a stratified sampling method. Descriptive analysis, food security index (FSI), coping strategy index (CSI) and binary regression logit models were used to analyze the data. Result reveals that 46 percent of the households were food secure. Main socioeconomic variables such as household head’s level of education, involvement in farming, expenditure, household size, farm size, age, livestock ownership and household member earning were significant in influencing household’s food security status. while the supply of modern inputs, challenges faced in accessing subsidized inputs, loan facility and amount, and extension service were the main variables of government intervention that influence household’s food security. Subsequently, variables related to conflicts such as low productivity, absence of extension agents and high cost of food and agricultural inputs, and security checkpoints operation were also significant in influencing household’s food security. CSI reveals that the most frequent and severe coping strategies adopted are; skipping meals for the whole day and selling assets/livestock. Results of this study recommended that government should create massive employment in agriculture sector, encourage business environment, sound education and family planning. Government’s owned ranches, cracking down of insurgents and carrot and stick should be considered to combat conflicts. Policies consistency and availability of funds should be a top priority by the government