Electric utility forecasting of customer cogeneration and the influence of special rates

Cogeneration, or the simultaneous production of heat and electric or mechanical power, emerged as one of the main components of the energy conservation strategies in the past decade. Special tax treatment, exemptions from fuel use restrictions, and regulatory policy changes were crafted to encourage its more wide-spread adoption in anticipation of higher energy conversion efficiencies. The expansion of cogeneration still faces a broad spectrum of problems, current and future: environmental restrictions; capital constraints; fuel prices; utility rates and future utility economics; and the difficulties of management.The most debated issue has been the reform of rates between individual cogenerators and the local electric utility. Many of the major cogeneration studies in the late 1970's urged an analysis of the exact impact from current electric utility rates upon cogeneration project economics (1,2,3). The changes mandated by the Public Utilities Regulatory Policy Act of 1978 (PURPA) are now reaching the final implementation stage and the cogeneration projects of the mid- 1970s are nearing completion. To better understand the relationship between utility rates, the economics of cogeneration, and its potential development, the New England Electric System and the Massachusetts Institute of Technology Energy Laboratory Utility Systems Group began a study to refine methods for forecasting cogeneration in a specific utility service area with special attention devoted to the utility rates (4).This paper surveys the insights gained from this effort, which is now nearing completion. Many of the central issues reflect conditions in New England, but this analysis should provide an approach for examining the question in other regions as well. Since the project has not undergone complete review, however, this paper reflects the opinions of the author alone

Cogeneration in the U.S. : an economic and technical analysis

Originally presented as the author's thesis, (M.S.) in the M.I.T. Dept. of Civil Engineering, 1978.Traditionally, only space heating and transportation have consumed more fuel than industrial process steam generation. Several recent studies have examined electricity and industrial steam supply and have recommended vigorous federal efforts to increase the cogeneration, or joint production, of electricity and process steam. The conceptual approach and analytic methods employed in these studies contain flaws that make them incomplete. The studies' recommendations are premised upon the existence of distortions in the markets surrounding cogeneration, but they offer only anecdotal evidence of such market failures. They propose increased cogeneration, citing aggregate energy savings for a single year and cumulative capital savings, but the analytic techniques they use in simulating market behavior and evaluating the desirability of various levels of cogeneration lack needed sophistication. This research addresses several of the methodological objections to the earlier studies. To unite this effort, the report poses two focal questions on cogeneration policy and economics: * Can the historical decline in cogeneration's importance be explained by changes in fuel prices and technologies alone? * What is the best future role for cogeneration if the choice is based on economic efficiency? First, the markets associated with cogeneration are examined from a qualitative perspective, employing the classic basic conditions/market structure/conduct/performance approach of industrial economics to explore the potential for inefficient market performance. Engineering production and cost functions are developed for a simple cogeneration plant design, offering insights into the economies of scale and joint production problems involved in the choice between cogeneration and separated production alternatives. Second, a multi-period linear programming model, called the Joint Generation Supply Model or JGSM, is form- ulated to simulate competitive market behavior in the aggregate U,S. electricity and process steam supply markets throughout a given time interval. JGSM is used to study the historical performance of these markets for 1960 to 1972 and the future role o cogeneration for 1975 to 2000, Appendices survey cogeneration technologies and the issues in integrating cogeneration plants into the utility system. The modeling of the historical question shows the decline can be explained by changes in cost conditions, but these results are very sensitive to the engineering cost assumptions. Analysis of cogeneration's future role indicates cogeneration should increase from its 4.5% share of electricity supply in 1975 to 9% in 1985; it should also serve more than half the process steam supply. If cogeneration remains at its 1975 share through 2000, the additional costs imposed are worth about $10 billion in discounted capital and operating expenses. Too much cogeneration can hurt as much as too little: forcing it up to a 20to another issue, JGSM calculated that failure to develop low-Btu coalgasifying combined cycle power technologies results in losses worth$4 billion.Research supported in part by the National Science Foundation and the U.S. Dept. of Energy

Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection

Multiplicity is one of the most fundamental observable properties of massive O-type stars and offers a promising way to discriminate between massive star formation theories. Nevertheless, companions at separations between 1 and 100 mas remain mostly unknown due to intrinsic observational limitations. [...] The Southern MAssive Stars at High angular resolution survey (SMASH+) was designed to fill this gap by providing the first systematic interferometric survey of Galactic massive stars. We observed 117 O-type stars with VLTI/PIONIER and 162 O-type stars with NACO/SAM, respectively probing the separation ranges 1-45 and 30-250mas and brightness contrasts of Delta H < 4 and Delta H < 5. Taking advantage of NACO's field-of-view, we further uniformly searched for visual companions in an 8''-radius down to Delta H = 8. This paper describes the observations and data analysis, reports the discovery of almost 200 new companions in the separation range from 1mas to 8'' and presents the catalog of detections, including the first resolved measurements of over a dozen known long-period spectroscopic binaries. Excluding known runaway stars for which no companions are detected, 96 objects in our main sample (DEC < 0 deg; H<7.5) were observed both with PIONIER and NACO/SAM. The fraction of these stars with at least one resolved companion within 200mas is 0.53. Accounting for known but unresolved spectroscopic or eclipsing companions, the multiplicity fraction at separation < 8'' increases to f_m = 0.91 +/- 0.03. The fraction of luminosity class V stars that have a bound companion reaches 100% at 30mas while their average number of physically connected companions within 8'' is f_c = 2.2 +/- 0.3. This demonstrates that massive stars form nearly exclusively in multiple systems. Additionally, the nine non-thermal (NT) radio emitters observed by SMASH+ are all resolved [...]Comment: 57 pages, 20 figures, 7 tables; accepted for publication in ApJ

The Asparagine Hydroxylase FIH: A Unique Oxygen Sensor

Significance: Limited oxygen availability (hypoxia) commonly occurs in a range of physiological and pathophysiological conditions, including embryonic development, physical exercise, inflammation, and ischemia. It is thus vital for cells and tissues to monitor their local oxygen availability to be able to adjust in case the oxygen supply is decreased. The cellular oxygen sensor factor inhibiting hypoxia-inducible factor (FIH) is the only known asparagine hydroxylase with hypoxia sensitivity. FIH uniquely combines oxygen and peroxide sensitivity, serving as an oxygen and oxidant sensor. Recent Advances: FIH was first discovered in the hypoxia-inducible factor (HIF) pathway as a modulator of HIF transactivation activity. Several other FIH substrates have now been identified outside the HIF pathway. Moreover, FIH enzymatic activity is highly promiscuous and not limited to asparagine hydroxylation. This includes the FIH-mediated catalysis of an oxygen-dependent stable (likely covalent) bond formation between FIH and selected substrate proteins (called oxomers [oxygen-dependent stable protein oligomers]). Critical Issues: The (patho-)physiological function of FIH is only beginning to be understood and appears to be complex. Selective pharmacologic inhibition of FIH over other oxygen sensors is possible, opening new avenues for therapeutic targeting of hypoxia-associated diseases, increasing the interest in its (patho-)physiological relevance. Future Directions: The contribution of FIH enzymatic activity to disease development and progression should be analyzed in more detail, including the assessment of underlying molecular mechanisms and relevant FIH substrate proteins. Also, the molecular mechanism(s) involved in the physiological functions of FIH remain(s) to be determined. Furthermore, the therapeutic potential of recently developed FIH-selective pharmacologic inhibitors will need detailed assessment. Antioxid. Redox Signal. 37, 913–935

Medial prefrontal cortex neuronal activation and synaptic alterations after stress-induced reinstatement of palatable food seeking: a study using c-fos-GFP transgenic female rats

Relapse to maladaptive eating habits during dieting is often provoked by stress and there is evidence for a role of ovarian hormones in stress responses and feeding. We studied the role of these hormones in stress-induced reinstatement of food seeking and medial prefrontal cortex (mPFC) neuronal activation in c-fos-GFP transgenic female rats, which express GFP in strongly activated neurons. Food-restricted ovariectomized or sham-operated c-fos-GFP rats were trained to lever-press for palatable food pellets. Subsequently, lever-pressing was extinguished and reinstatement of food seeking and mPFC neuronal activation was assessed after injections of the pharmacological stressor yohimbine (0.5-2 mg/kg) or pellet priming (1-4 noncontingent pellets). Estrous cycle effects on reinstatement were also assessed in wild-type rats. Yohimbine- and pellet-priming-induced reinstatement was associated with Fos and GFP induction in mPFC; both reinstatement and neuronal activation were minimally affected by ovarian hormones in both c-fos-GFP and wild-type rats. c-fos-GFP transgenic rats were then used to assess glutamatergic synaptic alterations within activated GFP-positive and nonactivated GFP-negative mPFC neurons following yohimbine-induced reinstatement of food seeking. This reinstatement was associated with reduced AMPA receptor/NMDA receptor current ratios and increased paired-pulse facilitation in activated GFP-positive but not GFP-negative neurons. While ovarian hormones do not appear to play a role in stress-induced relapse of food seeking in our rat model, this reinstatement was associated with unique synaptic alterations in strongly activated mPFC neurons. Our paper introduces the c-fos-GFP transgenic rat as a new tool to study unique synaptic changes in activated neurons during behavio

Global Health Needs Modernized Containment Strategies to Prepare for the Next Pandemic

COVID-19 continues to be a public health crisis, while severely impacting global financial markets causing significant economic and social hardship. As with any emerging disease, pharmaceutical interventions required time, emphasizing the initial and continuing need for non-pharmaceutical interventions. We highlight the role of anthropological and historical perspectives to inform approaches to non-pharmaceutical interventions for future preparedness. The National Academy of Medicine, a not-for-profit, non-governmental US-based medical watchdog organization, published a key document early in the COVID-19 pandemic which points to inadequate quarantine and containment infrastructure as a significant obstacle to an effective pandemic response. In considering how to implement effective quarantine policies and infrastructure, we argue that it is essential to take a longitudinal approach to assess interventions that have been effective in past pandemics while simultaneously addressing and eliminating the negative socio-historical legacies of ineffective quarantine practices. Our overview reinforces the need for social equity and compassion when implementing containment

Studies on the clinical significance of nonesterified and total cholesterol in urine

Gas-liquid chromatographic determinations of nonesterified and total urinary cholesterol were performed in 137 normals, 264 patients with various internal diseases without evidence of neoplasias or diseases of the kidney or urinary tract, 497 patients with malignancies and 236 patients with diseases of the kidney, urinary tract infections or prostatic adenoma with residual urine. A normal range (mean±2 SD) of 0.2–2.2 mg/24 hours nonesterified cholesterol (NEC) and of 0.3–3.0 mg/24 hours total cholesterol (TC) was calculated. Values of urinary cholesterol excretion were independent of age and sex and did not correlate with cholesterol levels in plasma. Patients with various internal diseases, without evidence of neoplasias nor diseases of the kidney or obstruction of the urinary tract, showed normal urinary cholesterol excretions, as did patients with infections of the urinary tract. However, elevated urinary cholesterol was found in patients with diseases of the kidney or urinary tract obstruction (prostatic adenoma with residual urine), malignant diseases of the urogenital tract and metastasing carcinoma of the breast. In patients with other malignant diseases urinary cholesterol was usually normal. Lesions of the urothelial cell membranes are considered to be the most likely cause of urinary cholesterol hyperexcretion. The clinical value of urinary cholesterol determinations as a possible screening test for urogenital carcinomas in unselected populations is limited by lacking specificity, expensive methodology and low prevalence of the mentioned carcinomas, although elevated urinary cholesterol excretions have been observed in early clinical stages of urogenital cancers

Electronic sculpting of ligand-GPCR subtype selectivity:the case of angiotensin II

GPCR subtypes possess distinct functional and pharmacological profiles, and thus development of subtype-selective ligands has immense therapeutic potential. This is especially the case for the angiotensin receptor subtypes AT1R and AT2R, where a functional negative control has been described and AT2R activation highlighted as an important cancer drug target. We describe a strategy to fine-tune ligand selectivity for the AT2R/AT1R subtypes through electronic control of ligand aromatic-prolyl interactions. Through this strategy an AT2R high affinity (<i>K</i>_i = 3 nM) agonist analogue that exerted 18,000-fold higher selectivity for AT2R versus AT1R was obtained. We show that this compound is a negative regulator of AT1R signaling since it is able to inhibit MCF-7 breast carcinoma cellular proliferation in the low nanomolar range