Structure of 2,9-dimethyl-1,10-phenanthroline hemihydrate

C14H12N2•½H2O, Mr = 217•27, tetragonal I41/a, a = 14•258 (3), c = 22•286 (4) Å, V = 4531 (3) Å3, Z = 16, Dx = 1•274 (1) g cm-3, Mo Kα radiation λ = 0•71073 Å, µ = 0•74 cm-1, F(000) = 1840, T = 297 K, R = 0•041 for 1196 unique observed reflections with I \u3e 2σ(I). Pairs of dimethylphenanthroline molecules related by a twofold axis are bridged by water molecules lying on the twofold axis and H bonded to one of the N atoms in each molecule. The H bonds are long and far from linear: O—H 1•06 (4), H•••N 154 (3)°. This is presumably a consequence of the approximately parallel arrangement of the two phenanthroline molecules in the (phen)2.H2O complex, which are tilted 4•7 (1)° with respect to each other; the atoms in one molecule are 3•50 to 3•81 Å from the plane of the other molecule. On the other side of the phenanthroline is another phenanthroline related by a center of symmetry with the atoms of one molecule 3•41 to 3•45 Å from the plane of the other molecule. The phenanthroline molecule has close to 2mm symmetry, but the individual C6 rings are tilted about 1° with respect to each other

High Profile Systems Illustrating Contradistinctive Aspects of Systems Engineering

AbstractMany modern systems have a high degree of dependence on embedded software in order to perform their required functions. Some examples include transportation systems, hand-held devices, and medical equipment, among others. In designing their products, systems engineers typically take a top-down, process-oriented approach, decomposing a complex system into simpler, easier to manage, subsystems; the system requirements can then be allocated and flowed down as necessary to the appropriate subsystems. Software engineers take a more bottom-up, object-oriented approach, using simple building blocks to create a more complex system, and enhancing their existing blocks with new ones where necessary.In many cases, both techniques must be employed together in order to design a successful system. Although it may have been acceptable in the past for simpler systems to view software as a separate subsystem with a fixed set of requirements, greater complexity of modern systems requires a corresponding improvement in working methodology. With the software playing an increasingly pivotal role, systems engineers must become much more familiar with the architecture of the software than previously; Likewise, software engineers need a systems-level view to understand which aspects of the design could be volatile due to new stakeholders (bringing with them new requirements), technology upgrades, and the changing world in general.Systems whose success or failure play out in the public arena provide a rare opportunity to study the factors that contribute to their outcome. Using two such systems, the Denver International Airport baggage handling system and the Apple iPad, this paper will study some best practices that can lead to project success or failure, and show the importance of a rigorous capture and flow down to both hardware and software of the requirements that must be correct from the start, as well as of designing an architecture that can accommodate the inevitable changes to a system.Designing extensible systems with a tolerance for future changes is a key factor in modern complex systems. The baggage handling system failed in part because of a failure to appreciate the central role of software and an apparent lack of a suitable strategy for handling requirement changes. Methods for creating software which is resilient to change have been well studied; however what may be somewhat lacking even to the present day is a broader education of the existing body of knowledge, and how to integrate it with systems engineering methods.The iPad succeeded where many of its predecessors had failed by a successful application of traditional systems engineering techniques and correctly implementing the hardware elements. Coming from companies with experience in software development, the system extensibility was not an issue in this case. However, the designers of the earlier systems seemingly failed to understand the actual market needs, failed to develop a corresponding set of requirements to meet those needs, and failed to translate those requirements into an integrated hardware/software solution

Stock assessment and management recommendations for Pacific sardine (Sardinops sagax) in 1997

The primary goal of sardine management as directed by the California Fish and Game Code is rehabilitation of the resource with an added objective of maximizing sustained harvest. Accordingly, the Code states that the annual sardine quota can be set at an amount greater than 1,000 tons, providing that the level of take allows for continued increase in the spawning population. We estimated the sardine population size to have been 464,000 short tons on July 1, 1997. Our estimate was based on output from a modified version of the integrated stock assessment model called CANSAR (Deriso et al. 1996). CANSAR is a forward-casting, age-structured analysis using fishery-dependent and fishery-independent data to obtain annual estimates of sardine abundance, year-class strength and age-specific fishing mortality for 1983 through the first semester of 1997. Non-linear least-squares criteria are used to find the best fit between model estimates and input data. Questions about stock structure and range extent remain major sources of uncertainty in assessing current sardine population biomass. Recent survey results and anecdotal evidence suggest increased sardine abundance in the Pacific Northwest and areas offshore from central and southern California. It is difficult to determine if those fish were part of the stock available to the California fishery. In an attempt to address this problem, the original CANSAR model was reconfigured into a Two-Area Migration Model (CANSAR-TAM) which accounted for sardine lost to the areas of the fishery and abundance surveys due to population expansion and net emigration. While the model includes guesses and major assumptions about net emigration and recruitment, it provides an estimate which is likely closer to biological reality than past assessments. The original CANSAR model was also used and estimates are provided for comparison. Based on the 1997 estimate of total biomass and the harvest formula used last year, we recommend a 1998 sardine harvest quota of 48,000 tons for the California fishery. The 1998 quota is a decrease of 11% from the final 1997 sardine harvest quota for California of 54,000 tons. (55pp.

On the Evolution of Islands

Let n cells be arranged in a ring, or alternatively, in a row. Initially, all cells are unmarked. Sequentially, one of the unmarked cells is chosen at random and marked until, after n steps, each cell is marked. After the kth cell has been marked the configuration of marked cells defines some number of islands: maximal sets of adjacent marked cells. Let ξ k denote the random number of islands after k cells have been marked. We give explicit expressions for moments of products of ξ k ’s and for moments of products of 1/ξ k ’s. These are used in a companion paper to prove that if a random graph on the natural number is made by drawing an edge betweeni≧1 andj\u3ei with probabilityλ/j, then the graph is almost surely connected ifλ\u3e1/4 and almost surely disconnected ifλ≦1/4

The Match Set of a Random Permutation Has the FKG Property

We prove a conjecture of Joag-Dev and Goel that if M = M(σ) = {i: σ(i) = i} is the (random) match set, or set of fixed points, of a random permutation σ of 1,2,…,n, then f(M) and g(M) are positively correlated whenever f and g are increasing real-valued set functions on 2{1,…,n}, i.e., Ef(M) g(M) ≥ Ef(M) Eg(M). No simple use of the FKG or Ahlswede-Daykin inequality seems to establish this, despite the fact that the FKG hypothesis is almost satisfied. Instead we reduce to the case where f and g take values in {0,1}, and make a case-by-case argument: Depending on the specific form of f and g, we move the probability weights around so as to make them satisfy the FKG or Ahlswede-Daykin hypotheses, without disturbing the expectations Ef, Eg, Efg. This approach extends the methodology by which FKG-style correlation inequalities can be proved

The Grizzly, November 20, 1981

Ursinus Takes First Step As Planning Gets Under Way • Successful Graduates Advise Seniors • Whatley Invited to Shuttle Launch • Ursinus\u27 Tuition Compared to Other Colleges • Sleigh Bells in September • Annual Messiah Concert Dec. 5 • Study Abroad Series: \u27Of Pints and Men\u27 • Variety Briefs: One-man band; Chamber orchestra performs; Cafe international • USGA Notes • Girls B-Ball Optimistic For New Season • Aquamen Drop Opener • Grapplers Do Well • Men\u27s B-Ball...Can They Do It Again? • Fine Showing in Regionals Sends Team to Wisconsin • Girls Splash to Victoryhttps://digitalcommons.ursinus.edu/grizzlynews/1068/thumbnail.jp

The Grizzly, November 13, 1981

Suspicious Visitor Causes Alarm • Whistle Blowing: The Problem of Ethics in Business • Two Students Caught In Breaking and Entering • Pledging Discussion • Student Teachers Putting in Their Hours • Powlette Speaks on Values • USGA Notes • Students Attend Orchestra Concert in Philadelphia • Ursinus Represented at PCCA Choir Festival • Winterfest Brings Culture Shock to UC • Study Abroad Series: Gidget Goes to Rome • UC Attempts \u27World\u27s Largest Sandcastle\u27 • Davis Selected All-American • Dickinson vs Bears in ECAC Championship • Student Plays for Peru in Pan Am Games • Swimmers Enthusiastic About New Season • Fencing Foils F&M • Bears End Disappointing Season With Loss • Grapplers Anxious To Begin • U.C. Harriers MAC Champs... Againhttps://digitalcommons.ursinus.edu/grizzlynews/1067/thumbnail.jp

Community Engaged Cumulative Risk Assessment of Exposure to Inorganic Well Water Contaminants, Crow Reservation, Montana

An estimated 11 million people in the US have home wells with unsafe levels of hazardous metals and nitrate. The national scope of the health risk from consuming this water has not been assessed as home wells are largely unregulated and data on well water treatment and consumption are lacking. Here, we assessed health risks from consumption of contaminated well water on the Crow Reservation by conducting a community-engaged, cumulative risk assessment. Well water testing, surveys and interviews were used to collect data on contaminant concentrations, water treatment methods, well water consumption, and well and septic system protection and maintenance practices. Additive Hazard Index calculations show that the water in more than 39% of wells is unsafe due to uranium, manganese, nitrate, zinc and/or arsenic. Most families’ financial resources are limited, and 95% of participants do not employ water treatment technologies. Despite widespread high total dissolved solids, poor taste and odor, 80% of families consume their well water. Lack of environmental health literacy about well water safety, pre-existing health conditions and limited environmental enforcement also contribute to vulnerability. Ensuring access to safe drinking water and providing accompanying education are urgent public health priorities for Crow and other rural US families with low environmental health literacy and limited financial resources

The Grizzly, October 2, 1981

Homecoming Celebration Takes on New Meaning • Previously Idle Appeals Procedure Finally Tested • Faculty Member\u27s Dismissal Creates Unrest • President Calls School Start \u27One of the Best Ever\u27 • Comment: I Thought This Was College • Parent Involvement Sought in Planning for the Future • Platforms for Freshman Class Elections • Greaseband Sings its Heart Out to Fortunate Few • Concert Causes Funds Loss • Transplanted Texan: Our Most Illustrious Non-Graduate • Rolling Stones Rock \u27n Roll Circus Levels JFK • Ursinus News Briefs: Postage hike finally granted; \u27Dealing with Stress\u27 offered by evening school • Campus Craziness: Sorority Pledging Begins • Red Cross Bloodmobile at HH • Women Receive Special Attention for Founder\u27s Day • Parents Day: Oct. 10 • Volleyball Holding Even • Soccer Registers First Win • Bears Surrender Lead to Tie Moravian at 10 • Hockey Pulls Out Win in Last Seconds • X-Country Makes it Look Easy . . . Againhttps://digitalcommons.ursinus.edu/grizzlynews/1062/thumbnail.jp